Chapter I

AMD Based Processor

AMD based processor Advanced Micro Devices, Inc. or AMD is an American multinational semiconductor company and its main products include microprocessors, motherboard chipsets, embedded processors and graphics processors for servers, workstations and personal computers, and embedded systems applications. It is the second-largest global supplier of microprocessors based on the x86 architecture and also one of the largest suppliers of graphics processing units.

ActiveX and Java

ActiveX and Java ActiveX is a technology that's embedded into many Web sites to enrich browsing experience. ActiveX feature can be used for things like playing videos, displaying animations, and viewing certain kinds of files. It can also pose security risks and slow down your computer. Java environment is also required in some Web sites to use some advance pages. It is often required in playing videos, online exam taking sites, online games, etc.

Bluetooth

Bluetooth Bluetooth is a standard for very low-powered and short-range radio connections. It is used to link personal access devices (PDA), mobile phones and laptops, and provides them with Internet access via hot spots. Bluetooth uses the 2.4 Hz spectrum with a data rate of about 1 Mbps. Unlike infrared radio connections, Bluetooth does not require line of sight. The maximum transmission range of Bluetooth is around 10 meters. High-powered Bluetooth would extend the range to 100 meters.

Browser Features

Browser features A Web browser is responsible for displaying platform-independent Web pages written in Hypertext Markup Language (HTML). It displays images and responds to hyperlinks on a Web page. For each new Web page request to the Web server, the Web browser clears the browser screen with the current Web pages in order to display the new Web page on the browser.

Bus Differences

Bus differences In computer terms, a bus is a communication pathway. A computer system has multiple buses to enable communication between the various components of the PC. A bus is defined by various characteristics such as how many bits it can transmit at one time and which signaling techniques are used across it. A computer system has the following types of buses: Address Data Expansion Video

CAT5 Cables

CAT5 cables Following are the different types of network cabling: CAT 3: It is a category 3 twisted pair cabling (10BaseT) and supports a speed of up to 10 Mbps. CAT 5: It is a category 5 twisted pair cabling (100BaseT) and supports a speed of up to 100 Mbps. CAT5e: It is a category 5e twisted pair cabling (1000BaseT) and supports a speed of up to 1000 Mbps. CAT 6: It is a category 6 twisted pair cabling (1000BaseT) and supports a speed of up to 1000 Mbps.

Cache Size

Cache size Hard drive cache, also known as disk cache or cache buffer, is the embedded memory in a hard drive acting as a buffer between the rest of the computer and the physical hard disk platter that is used for storage. Modern hard disks come with 8 to 64 MB of cache memory.

Cell Based Processor

Cell based processor Cell is a microprocessor architecture jointly developed by Sony, Sony Computer Entertainment, Toshiba, and IBM, an alliance known as 'STI'. It is a microprocessor designed to bridge the gap between conventional desktop processors, such as the Athlon 64, and Core 2 families and more specialized high-performance processors, such as the NVIDIA and ATI graphics-processors (GPUs).

Compatibility Issues of RAM in a computer

Compatibility issues of RAM in a computer A speed notation standard has been created by memory and manufacturers to choose the correct memory. It is advised to look into the user manual of respective motherboards to choose right memory for your system. Incorrect RAM type will not work effectively in your computer. RAM is an important component of your system. A minimum amount of RAM is required by many applications. Having less RAM than specified can prevent you from executing these applications.

Cookies

Cookies Cookies are small pieces of information. Cookies contain information that is sent to the client computer to be stored in the memory or a text file in the client's hard drive. Cookies are not software. Cookies cannot be programmed, cannot carry viruses, and cannot install malware on the host computer. Cookies are often sent by a server from a site that the user has visited, but can also be set on the client side using JavaScript.

Customizations

Customizations (text sizes, text styles, etc.) A Web browser can be customized according to user requirements. A user can customize text sizes, text styles; download locations, plug-ins, etc. A variety of Web browsers are available as a freeware, such as Google Chrome, Mozilla Firefox, Internet Explorer, Safari, Opera, etc. All these browsers support several customizations, for example setting a home page, blocking web sites, pop-up blockers, etc.

DDR RAM

DDR RAM Double data rate synchronous dynamic random-access memory (DDR SDRAM) is a class of memory integrated circuits used in computers. DDR SDRAM, sometimes referred to as DDR1 SDRAM, has been superseded by DDR2 SDRAM and DDR3 SDRAM, neither of which are either forward or backward compatible with DDR SDRAM, meaning that DDR2 or DDR3 memory modules will not work in DDR equipped motherboards, and vice versa.

DHCP

DHCP Dynamic Host Configuration Protocol (DHCP) is a TCP/IP standard used to dynamically assign IP addresses to computers, so that they can communicate with other network services. It reduces the complexity of managing network client IP address configuration. A DHCP server configures DHCP-enabled client computers on the network. It runs on servers only. It also provides integration with Windows Active Directory service. DHCP uses ports 67 and 68 for communication.

Dual Core Processor

Dual core processor A dual core processor is a CPU with two separate cores in the same chip. Each core has its own cache. A dual core processor is an equivalent of two microprocessors in a computer. In a dual core processor, both cores handle incoming data strings simultaneously, resulting in improved efficiency. Hence, a dual core system is faster than a single-core or traditional processor system. A dual core processor does not require a new motherboard, but can be used in existing boards having the correct socket. Intel and AMD are the companies that are making dual core processors.

FTP

FTP File Transfer Protocol (FTP) is a primary protocol of the TCP/IP protocol suite. It is used to transfer text and binary files between computers over a TCP/IP network. FTP uses TCP ports 20 and 21 for communication.

Gamepad

Gamepad A gamepad, also known as a joypad, is the most common kind of game controller, held in both hands with thumbs and fingers used to provide input. Gamepads can have from two buttons to a dozen or more, combined with multiple omnidirectional analogue or digital control sticks.

Internet

Internet The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite (often called TCP/IP, although not all applications use TCP) to serve billions of users worldwide. It is a network of networks that consists of millions of private, public, academic, business, and government networks, of local to global scope, that are linked by a broad array of electronic, wireless and optical networking technologies.

Internet Cache

Internet Cache When a page is downloaded by a web browser, copies of the page are stored in a cache located on the hard drive. This consists of text from the web pages, graphics, and some audio and video files that are not streamed. If the page has to be reloaded, the contents are not downloaded from the Internet but are retrieved from the cache. This cache improves the speed when displaying web pages, but also uses a lot of disk space.

Mobile Media Devices

Mobile media devices Mobile media devices, such as mobile phones, mp3 players, and PDA's are the primary source of portable media from which we can obtain information and communicate with one another. A personal digital assistant (PDA) is a mobile device that functions as a Personal information manager and connects to the Internet. A MP3 player is also a mobile media device that can hold hundreds of mp3 songs.

PC Speed/storage capability

PC Speed/storage capability Increasing RAM almost always improves the computer's performance. When there is insufficient RAM, the CPU has to work more by shuffling data between RAM and the page file.

Speakers

Speakers Computer speakers, or multimedia speakers, are speakers external to a computer that disable the lower fidelity built-in speaker. They often have a low-power internal amplifier. The standard audio connection is a 3.5 mm (approximately 1/8 inch) stereo jack plug often color-coded lime green (following the PC 99 standard) for computer sound cards. A plug and socket for a two-wire (signal and ground) coaxial cable is widely used to connect analog audio and video components. Rows of RCA sockets are found on the backs of stereo amplifier and numerous A/V products. The prong is 1/8" thick by 5/16" long. A few use an RCA connector for input. There are also USB speakers which are powered from the 5 volts at 500 milliamps provided by the USB port, allowing about 2.5 watts of output power.

Standard vs. crossover cables

Standard vs. crossover cables An Ethernet crossover cable is a type of Ethernet cable used to connect computing devices together directly. Normal straight through or patch cables were used to connect from a host network interface controller to a network switch, hub or router. A cable with connections that 'cross over' was used to connect two devices of the same type: two hosts or two switches to each other.

TCP/IP

TCP/IP Transmission Control Protocol/Internet Protocol (TCP/IP) is a suite of standard protocols that govern how data passes between networks. It can be used to provide communication between the basic operating systems, on local and wide-area networks (WANs). TCP/IP is considered as the primary protocol suite for the Internet and the World Wide Web.

Tablet

Tablet (touch screen) A tablet PC is a wireless, portable personal computer with a HYPERLINK "http://searchcio-midmarket.techtarget.com/definition/touch-screen" touch screen interface. The tablet form factor is typically smaller than a notebook computer but larger than a smart phone. It uses an onscreen virtual keyboard, a passive stylus pen, or a digital pen.

802.11a

802.11a 802.11a is an amendment to the IEEE 802.11 specification that added a higher data rate of up to 54 Mbit/s using the 5 GHz band. It has seen widespread worldwide implementation, particularly within the corporate workspace. The amendment has been incorporated into the published IEEE 802.11-2007 standard.

802.11b

802.11b 802.11b is one of the most popularly used 802.1x technologies. It uses Direct Sequence Spread Spectrum (DSSS), and its capacity per channel is 11 Mbps with real throughput at about 6 Mbps. It operates at a frequency of 2.4 GHz, which supports three non-overlapping channels.

802.11g

802.11g 802.11g is a combination of 802.11a and 802.11b. It can use either Direct Sequence Spread Spectrum (DSSS) or Orthogonal Frequency Division Multiplexing (OFDM) to transmit data. Its capacity per channel is 54 Mbps with real throughput at about 12 Mbps. It operates at a frequency of 2.4 GHz. 802.11g is a popularly used 802.11 technology.

802.11n

802.11n IEEE 802.11n is a wireless networking standard to improve network throughput over the two previous standards: 802.11a and 802.11g. It supports data rate from 54 MBPS to 600 MBPS with the use of four spatial streams at a channel width of 40 MHz.

Anti-Phising Features

Anti-phishing features The new versions of both Microsoft's and Mozilla's Internet browsers have anti-phishing functionality, including components that check Web sites for validity before it opens up the Web page for viewing. Explorer has a built-in Anti-Phishing feature using Phishing Filter. Phishing Filter in Internet Explorer helps detect phishing websites.

Application

Application Application software and tools are used to add more functionality to computer system. Application software helps a user to accomplish their task easily and effectively.

Auto-negotiating (speed and duplex)

Auto-negotiating (speed and duplex) Auto-negotiation is an Ethernet procedure by which two connected devices choose common transmission parameters, such as speed, duplex mode, and flow control. In auto-negotiation, the connected devices first share their capabilities regarding these parameters and then choose the highest performance transmission mode they both support. In the OSI model, auto-negotiation resides in the physical layer. Auto-negotiation can be used by devices that are capable of different transmission rates, different duplex modes (half duplex and full duplex), and different standards at the same speed.

Automatic application and operating system updates

Automatic application and operating system updates Updates of an application or an operating system are important because they are the new version of the same software or operating system and help in eliminating bugs of the installed version. Updated version of an application or an operating system also provides some new features.

Bandwidth and contention ratio

Bandwidth and contention ratio The contention ratio is the ratio of the potential maximum demand to the actual bandwidth. The higher the contention ratio, the greater the number of users that may be trying to use the actual bandwidth at any one time and, therefore, the lower the effective bandwidth offered, especially at peak times.

Blu-ray Disc

Blu-ray Disc Blu-ray Disc, also known as Blu-ray or BD, is an optical disc storage medium. It is designed to supersede the standard DVD format for storing high-definition video, PlayStation 3 games, and other data, with up to 25 GB per single layered, and 50 GB per dual layered disc. Blu-ray Disc was developed by the Blu-ray Disc Association, a group representing makers of consumer electronics, computer hardware, and motion pictures. The disc has the same physical dimensions as standard DVDs and CDs. It is called Blu-ray Disc because of the blue-violet laser which is used to read the disc. Blu-ray uses a shorter wavelength, a 405 nm blue-violet laser, and allows for almost six times more data storage than on a DVD.

Broadband Router

Broadband router A broadband router is used to connect 2 networks together. It is used to connect two LANs (Local Area Networks), two WANs (Wide Area Networks), or a LAN to the internet.

Bus Speed

Bus speed A bus is a circuit that connects one part of the motherboard to another. The more data a bus can handle at one time, the faster it allows information to travel. The speed of the bus is measured in megahertz (MHz). Bus speed refers to the speed of the front side bus (FSB), which connects the CPU to the Northbridge. FSB speeds can range from 66 MHz to over 800 MHz.

CD/CD-RW Drive

CD/CD-RW Drive CD drives are standard on computers today. In fact, many computers no longer contain a floppy drive unless the buyer selects it as an option. CD drives come in two types: CD-ROM drive: Can only read CDs. CD-RW drives: Can read from and write to CDs. When a CD contains computer data, the data stays in digital format. If the CD is an audio CD, a digital-to-analog converter converts the digital information into analog sound. CD drives contain three major parts: The drive motor spins the disc. The laser lens and laser pickup focuses in on and reads the disc. The tracking drive and tracking motor moves the laser to follow the track on the CD.

Compatibility Issues

Compatibility issues Open source operating systems, such as Linux, UNIX, etc., and commercial operating systems such as Windows OS both have sometimes compatibility issues. Device driver software of removable media and external devices do not support and gives errors. These issues can be resolved by contacting customer care or technical support team of respective OS providers. Users can also look for the right type of driver software on the Web. It is very important to read instructions and requirements before installing any new hardware/software.

DDR2 SDRAM

DDR2 SDRAM DDR2 SDRAM is a type of memory module. DDR2 SDRAM is an enhanced version of DDR SDRAM. It uses a 240-pin memory module and runs at the speed of 400 MHz or higher. It uses an operating voltage of 1.8 volts, instead of 2.5 volts used in DDR SDRAM. This results in less power consumption. DDR2 SDRAM transfers 64 bits of data twice every clock cycle. DDR2 SDRAM memory is not compatible with DDR SDRAM memory slots.

DDR3 SDRAM

DDR3 SDRAM DDR3 SDRAM or double-data-rate three synchronous dynamic random access memory is a random access memory interface technology used for high bandwidth storage of the working data of a computer or other digital electronic devices. DDR3 is part of the SDRAM family of technologies and is one of the many DRAM implementations. DDR3 SDRAM is an improvement over its predecessor, DDR2 SDRAM, and the two are not compatible. The primary benefit of DDR3 is the ability to transfer at twice the data rate of DDR2, thus enabling higher bus rates and higher peak rates than earlier memory technologies. DDR3 memory power consumption is 30 percent less as compared to DDR2 modules.

DIMMs vs. SODIMMs

DIMMs vs. SODIMMs Dual In-line Memory Module (DIMM) is a type of memory module that comes with 168 and 184 pins. A DIMM slot is larger than a SIMM slot. DIMM with 168 pins has two notches on its base. 184-pin DIMMs are for DDR SDRAM modules which are available in Pentium III and Pentium 4 and Athlon systems. 184-pin DIMMs are available in PC2100, PC2700, PC3200, and PC3500, and faster. The number of chips on a 184-pin DIMM may vary, but they have 92 pins on both sides of DIMM for a total of 184. 184-pin DIMMs are 5.375" long and 1.375" high, and the heights may vary. DIMMs have a small notch on the bottom of the module. A SO-DIMM, or small outline dual in-line memory module, is a type of computer memory built using integrated circuits. SO-DIMMs (also written SODIMMs) are a smaller alternative to a DIMM, being roughly half the size of regular DIMMs. SO-DIMMs are often used in systems which have space restrictions such as notebooks, small footprint PCs, high-end upgradable office printers, and networking hardware like routers.

DNS

DNS Domain Name System (DNS) is a hierarchical naming system used for locating domain names on private TCP/IP networks and the Internet. It provides a service for mapping DNS domain names to IP addresses and vice versa. DNS enables users to use friendly names to locate computers and other resources on an IP network. TCP/IP uses IP addresses to locate and connect to hosts, but for users, it is easier to use names instead of IP address to locate or connect to a site. For example, users will be more comfortable in using the host name www.uCertify.com rather than using its IP address 66.111.64.227. DNS uses TCP and UDP ports 53 for communication.

DSL and Cable Modems

DSL and cable modems A DSL modem is a device used to connect a single computer or router to a DSL phone line, in order to use an ADSL service. Like other modems, it is a type of transceiver. It is also called a DSL Transceiver or ATU-R. The acronym NTBBA is also common in some countries. Some of the ADSL modems also manage the connection and sharing of the ADSL service with a group of machines: in this case, the unit is termed a DSL router or residential gateway. DSL routers have a functional block, which performs framing, while other functional blocks perform Asynchronous Transfer Mode Segmentation and Reassembly, IEEE 802.1D bridging and/or IP routing. User interfaces are Ethernet and USB. Although an ADSL modem working as a bridge does not need an IP address, it may have one assigned for management purposes. A cable modem is a type of Network Bridge and modem that provides bi-directional data communication via radio frequency channels on a cable television (CATV) infrastructure. Cable modems are primarily used to deliver broadband Internet access in the form of cable Internet, taking advantage of the high bandwidth of a cable television network. They are commonly deployed in Australia, Europe, and North and South America. Many cable TV operators provide Internet connection through the cables to houses and offices that have cable TV connections. These connections require a cable modem to access the Internet. It provides speeds of up to 10 Mbps, though the average speed one gets is between 1.5 Mbps to 3 Mbps.

Data loss

Data loss Data loss can also take place during/after upgradation of an operating system. If you install a different OS, some of the data may not come in its original form due to file system changes. It is also noticed that creation/deletion of partition will result in loss of data. It is advised to take backup of your data before installing/upgrading a computer system.

Desktop

Desktop A desktop computer is a personal computer in a form intended for regular use at a single location. It is not specifically designed for portability because of the size and number of its major components and the connections between them. Nowadays desktop computers are available in stand-up vertical designs known as towers. In the past, they were available in horizontal lay flat designs. The advantage that the tower style desktop has over the horizontal desktop is that the tower desktop does not necessarily have to be placed on the desk. It can be placed on the floor or a mounting bracket or a stand open additional desktop space.

Digital Camera

Digital camera A digital camera is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor. Digital cameras can do things that film cameras cannot, such as displaying images on a screen immediately after they are recorded, storing thousands of images on a single small memory device, recording video with sound, and deleting images to free storage space. Some can crop pictures and perform other elementary image editing. Digital cameras are incorporated into many devices ranging from PDAs and mobile phones (called camera phones) to vehicles. The Hubble Space Telescope and other astronomical devices are essentially specialized digital cameras.

Ethernet Technologies

Ethernet technologies Ethernet is a family of computer networking technologies for local area networks (LANs). Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies. In the OSI reference system, Ethernet is at the Data Link layer.

Flash Based Hard Drives VS Traditional Hard Drives

Flash based hard drives vs. traditional hard drives Flash drives are typically no more than two to three inches in length and less than an inch in width. Their size and shape may resemble a thumb or a small pen. Traditional hard drives are used for storing and retrieving digital information, primarily computer data. It consists of one or more rigid rapidly rotating discs (platters) coated with magnetic material, and with magnetic heads arranged to write data to the surfaces and read it from them.

GHz VS MHz

GHz vs. MHz Processor is a major component of a computer system. The performance of a computer system depends on the speed of the processor. The processor speed is measured in terms of GHz and MHz. For Example, Intel Core i7 processor speed is 2.2 GHz. A gigahertz (GHz) is a unit of measurement that defines the clock rate of a computer processor. The clock rate determines how fast the CPU can finish an electronic circuit cycle and, in turn, helps determine the speed of the computer processor. GHz simply refers to the number of calculations a computer can complete in one second MHz stands for Mega Hertz, which is one million cycles per second or Hertz. It is used to measure the transmission speed of the computer's internal clock, buses, and channels. A one-megahertz clock (1 MHz) means that some number of bits can be manipulated at least one million times per second.

HTTP vs. HTTPS

HTTP vs. HTTPS Hypertext Transfer Protocol (HTTP) is a client/server TCP/IP protocol used on the World Wide Web (WWW) to display Hypertext Markup Language (HTML) pages. HTTP defines how messages are formatted and transmitted, and what actions Web servers and browsers should take in response to various commands. For example, when a client application or browser sends a request to the server using HTTP commands, the server responds with a message containing the protocol version, success or failure code, server information, and body content, depending on the request. HTTP uses TCP port 80 as the default port. HTTPS is an encrypted form of the HTTP protocol, which is used to protect end users from submitting private information to a rogue server impersonating another server. HTTPS is designed to coexist with the messaging model of HTTP and to be easily integrated with HTTP applications. It does not require client-side public key certificates, as it supports symmetric key-only operation modes. This is significant because it means that spontaneous private transactions can occur without requiring individual users to have an established public key. Strictly speaking, HTTPS is not a separate protocol, but refers to use of ordinary HTTP over an encrypted Secure Sockets Layer (SSL) or Transport Layer Security (TLS) connection. This ensures reasonable protection from eavesdroppers and man-in-the-middle attacks, provided that adequate cipher suites are used and that the server certificate is verified and trusted. HTTPS uses port 443 for communication.

Hard Drive

Hard drive Hard drive is used to store users' data as well as operating system files. Data stored on it can be accessed quickly. Hard disk drive is generally installed inside the computer case. It can store large amount of data. It provides fast read/write performance. HDD can be connected to a computer by the Integrated Device Electronics (IDE), Small Computer System Interface (SCSI), and SATA interface. It consists of inflexible platters coated with material in which data is recorded magnetically with read/write heads.

Hardware Failure

Hardware failure A malfunction within the electronic circuits or electro-mechanical components (disks, tapes) of a computer system. Recovery from a hardware failure requires repair or replacement of the offending part. Major reasons of hardware failure include using wrong hardware devices. CPU has to work more in case of minimum requirement of any tool is not followed, and in such cases hardware failure occur.

Home Plug (Ethernet over Power)

Home Plug (Ethernet over Power) Home plug Ethernet over power adaptors simply plug in two adaptors into the ordinary power sockets, one at each end of the network you want to connect. It immediately increases the coverage of the broadband router. It is easy to set up a home network using Home plug Ethernet over power adaptors. Combined with a router, and even Wi-Fi, a user can extend their home network all round, giving everyone in house access to the broadband connection.

IDE

IDE IDE (Integrated Drive Electronics) is a standard electronic interface used between a computer motherboard's data paths and the computer's disk storage devices. The IDE interface is based on the IBM PC Industry Standard Architecture (ISA) 16-bit bus standard, but it is also used in computers that use other bus standards. Most computers sold today use an enhanced version of IDE called Enhanced Integrated Drive Electronics (EIDE).

IMAP

IMAP Internet Message Access Protocol (IMAP or IMAP4) is a prevalent Internet standard protocol for e-mail retrieval. It is an application layer Internet protocol operating on port 143 that allows a local client to access e-mail on a remote server. IMAP supports both connected (online) and disconnected (offline) modes of operation. E-mail clients using IMAP generally leave messages on the server until the user explicitly deletes them. This and other facets of IMAP operation allow multiple clients to access the same mailbox.

Inter Based Processor

Intel based processor Intel Corporation is the inventor of the x86 series of microprocessors, the processors found in most personal computers. It is the world's largest and highest valued semiconductor chip maker based on revenue. Intel started with 4-bit Intel 4004 processor and presently they are offering 64-bit processors, such as core i3, core i5, and core i7.

Interference

Interference In communications and networking, interference is anything which alters, modifies, or disrupts a signal as it travels along a channel between a source and a receiver. The term refers to the addition of unwanted signals to a useful signal.

Internal VS External Hard Drive

Internal vs. external hard drive A hard disk is a storage device that a computer uses to store information. It is kept in a self-contained box called the hard disk drive. Internal hard disks are less prone to damage because they are installed inside the system. A computer can write to and read from an internal hard disk much faster in comparison to a removable disk. An external hard drive is attached to the computer through a USB port. External hard drives provide additional storage space and eliminate the requirement of installing another internal hard disk. External hard disks are a good option for backing up data because they can be easily removed for secure storage or for copying files to another computer.

Keyboard

Keyboard A keyboard is a standard input device. It is partially modeled after the typewriter keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches. It has characters engraved or printed on the keys and each press of a key corresponds to a single written symbol. A keyboard is used to type text and numbers into a word processor, text editor or other program. A computer keyboard distinguishes each physical key from every other and reports all key presses to the controlling software. Keyboards are also used for computer gaming, either with regular keyboards or by using keyboards with special gaming features, which can expedite frequently used keystroke combinations. A keyboard is also used to give commands to the operating system of a computer, such as Windows' Control-Alt-Delete combination, which brings up a task window or shuts down the machine.

Laptop

Laptop A laptop is a type of portable computer. It is designed for mobile use and small and light enough to sit on a person's lap while in use. It integrates most of the typical components of a desktop computer, including a display, a keyboard, a pointing device (touchpad or trackpad, pointing stick), speakers, and often including a battery, into a single small and light unit. Laptops are usually notebook-shaped with thicknesses between 0.7-1.5 inches (18-38 mm) and dimensions ranging from 10x8 inches (27x22cm, 13" display) to 15x11 inches (39x28cm, 17" display) and up. Modern laptops weigh 3 to 12 pounds (1.4 to 5.4 kg); older laptops were usually heavier. Most laptops are designed in the flip form factor to protect the screen and the keyboard when closed.

Local VS network shares

Local vs. network shares A user can share their hard drive access on local basis within an organization. To prevent data loss, access can be given in read only mode. Local shares help users/employees of an organization to view/edit information. Network shares refer to sharing your hard drive across a distance with the help of a network.

Microphone

Microphone A microphone is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. Microphones are used in many applications, such as telephones, tape recorders, karaoke systems, hearing aids, motion picture production, live and recorded audio engineering, FRS radios, megaphones, in radio and television broadcasting and in computers for recording voice, speech recognition, VoIP, and for non-acoustic purposes such as ultrasonic checking or knock sensors. Most microphones today use electromagnetic induction, capacitance change, piezoelectric generation, or light modulation to produce an electrical voltage signal from mechanical vibration.

Monitors

Monitors A monitor or display is an electronic visual display for computers. It is also known as visual display unit. A monitor comprises the display device, circuitry, and an enclosure. The display device in modern monitors is typically a thin film transistor liquid crystal display (TFT-LCD), while older monitors use a cathode ray tube (CRT). The performance of a monitor is measured through luminance, aspect ratio, display resolution, dot pitch; refresh rate, response time, contrast ratio, power consumption, and viewing angle.

Mouse

Mouse A mouse is a standard input device. It is a pointing device that functions by detecting two-dimensional motion relative to its supporting surface. It translates motion of the user's hand into electrical signals so that the PC converts into movement to track a pointer across the monitor's display, which allows for fine control of a graphical user interface.

Multi-card reader and writer

Multi-card reader and writer A card reader is a data input device that reads data from a card-shaped storage medium. Historically, paper or cardboard punched cards were used during the first several decades of the computer industry to store information and programs for computer systems; these were read by punched card readers. Card readers have subsequently been developed into electronic devices that are compatible with plastic cards embedded with a barcode, magnetic strips, computer chips or other storage medium.

Netbook

Netbook Netbooks (sometimes also called mini notebooks or ultra-portables) are a branch of subnotebooks, a rapidly evolving category of small, light, and inexpensive laptop computers suited for general computing and accessing web-based applications; they are often marketed as "companion devices," that is, to augment a user's other computer access. Walt Mossberg called them a "relatively new category of small, light, minimalist, and cheap laptops.

Networking

Networking A network is simply a collection of computers or other hardware devices that are connected together, either physically or logically, using special hardware and software, to allow them to exchange information and cooperate. Networking is the term that describes the processes involved in designing, implementing, upgrading, managing, and otherwise working with networks and network technologies.

Numeric Keypad

Numeric keypad A numeric keypad, numpad, or tenkey for short, is the small, palm-sized, seventeen-key section of a computer keyboard, usually on the very far right. The numeric keypad features digits 0 to 9, addition (+), subtraction (-), multiplication (*) and division (/) symbols, a decimal point (.), and Num Lock and Enter keys. Laptop keyboards often do not have a numpad, but may provide numpad input by holding a modifier key (labelled "Fn") and operating keys on the standard keyboard. Particularly large laptops (typically those with a 17-inch screen or larger) may have space for a real numpad, and many companies sell separate numpads which connect to the host laptop by a USB connection. It also provides a calculator-style keyboard for efficient entering of numbers.

Operating Systems

Operating systems (open source and commercial) An operating system is software that provides an interface between the hardware and user. It is responsible for management and coordination of processes and allocation and sharing of hardware resources, such as RAM and disk space, and acts as a host for computing applications running on the OS. It also provides orderly accesses to the hardware by competing software routines. Operating systems offers a number of services to application programs. Open source operating systems are freeware software. There is no need to pay for the open source operating system software. Open source operating system software are available on Internet and user can download them. For example: Ubuntu, Knoppix, Haiku, Syllable, Linux, etc. Commercial operating systems are paid software and users need to buy their license key. For example: Windows 7, Windows XP, Windows Vista, etc.

PDA

PDA A personal digital assistant (PDA), also known as a palmtop computer, is a mobile device that functions as a Personal information manager and connects to the Internet. The PDA has an electronic visual display, enabling it to include a web browser, but some newer models also have audio capabilities, enabling them to be used as mobile phones or portable media players. Many PDAs can access the Internet, intranets, or extranets via Wi-Fi, or Wireless Wide Area Networks (WWANs). Many PDAs employ touch screen technology.

POP3

POP3 Post Office Protocol version 3 (POP3) is an application-layer Internet standard protocol used by local e-mail clients to retrieve e-mail from a remote server over a TCP/IP connection. The design of POP3 and its procedures supports end-users with intermittent connections (such as dial-up connections), allowing these users to retrieve e-mail when connected and then to view and manipulate the retrieved messages without needing to stay connected. Although most clients have an option to leave mail on server, e-mail clients using POP3 generally connect, retrieve all messages, store them on the user's PC as new messages, delete them from the server, and then disconnect. POP3 works over a TCP/IP connection using TCP on network port 110. E-mail clients can encrypt POP3 traffic using TLS or SSL.

Plug-ins

Plug-ins In computing, a plug-in (also called add-in, addon, add-on, snap-in) is a computer program that cooperates with a host application to provide a specified function "on demand". Add-on is often referred to as the general term including plug-ins, extensions, and themes as subcategories.

Portable Devices

Portable devices Laptop, PDA, Smartphone, and Netbook are some examples of Portable devices. These devices are very small in comparison to a personal computer. These devices provide mobility with fast processing speed.

Printer/Scanner

Printer/Scanner A printer is a peripheral device, which produces a permanent readable text and/or graphics of documents stored in the electronic form, usually on physical print media such as paper or transparencies. Printers are routinely classified by the underlying print technology they employ. The choice of print engine has a substantial effect on what jobs a printer is suitable for, as different technologies are capable of different levels of image/text quality, print speed, low cost, and noise. A scanner is a device that optically scans an image, printed text, handwriting, or an object, and then converts it to a digital image. Common scanners found in offices are variations of the desktop (or flatbed) scanner, where the document is placed on a glass window for scanning and hand-held scanners, where the device is moved by hand.

Processor Cache Size

Processor cache size A processor cache enables the CPU to access recently used information very quickly. It significantly affects CPU performance. Some caches are bigger than others. A typical L1 cache is 256Kb and a typical L2 cache is 1MB. The larger the cache, the better the system performance boost.

Processor Speed/ Cores

Processor speed/cores Processor speed is also known as CPU speed. It is the amount of cycles that a CPU can perform per second. This is otherwise known as a Hertz. For example, one Hertz means that one cycle can be completed in one second and a megahertz means that one million cycles can be completed in a second. A gigahertz, the most common form of CPU speed, means that one billion cycles can be completed per second.

Protocols

Protocols A protocol is a system of digital message formats and rules for exchanging messages in or between computing systems. A protocol may have a formal description. A protocol includes signaling, authentication and error detection and correction capabilities. A protocol definition defines the syntax, semantics, and synchronization of communication.

Quad Core Processor

Quad core processor Quad core processor is a type of multi-core technology that includes two separate dual-core dies, where dial-core means a CPU that includes two complete execution cores per physical processor, installed together in one CPU package. In this set-up, cores 1 and 2 would share a memory cache, as would cores 3 and 4. If core 1 or 2 needs to communicate with 3 or 4, it is an external communication, usually via the front-side bus. Both Intel and AMD have introduced quad-core processors, starting with Intel in late 2006.

RAM

RAM RAM stands for random access memory. Random access means each memory location can be accessed in any order not necessarily in a sequential manner. It provides volatile storage that means data is not retained in the absence of electric power. To get data saved permanently one must transfer the contents from RAM to disk before switching off the system. Like microprocessor a memory too is made of millions of transistors.

RPMs

RPMs RPM is used to help determine the access time on computer hard disk drives. RPM is a measurement of how many complete revolutions a computer's hard disk drive makes in a single minute. The higher the RPM, the faster the data will be accessed; for example, if you were comparing two hard disk drives, one with 5400 RPM and another with 7200 RPM, the hard disk drive with a 7200 RPM will be capable of accessing data much faster than the 5400 RPM drive. However, it is also important to note that a 5400 RPM drive will be much cheaper than a 7200 RPM drive.

Radio Frequency (RF)

Radio frequency (RF) Radio frequency (RF) is a rate of oscillation in the range of about 3 KHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals. RF usually refers to electrical rather than mechanical oscillations, although mechanical RF systems do exist.

Risks of automatic updates

Risks of automatic updates Automatic software updates are supposed to make system more stable and faster. But vulnerable updating mechanisms can help hackers to attack the system. Automatic updates are also time consuming depending on their size. It also consumes Internet bandwidth without your consent. Some of the updates may not be necessarily required by the system so it will slow down your system during installing the updates.

SATA

SATA The Serial ATA (SATA) computer bus is a storage-interface for connecting host bus adapters to mass storage devices, such as hard disk drives and optical drives. SATA offers several compelling advantages over the older parallel ATA (PATA) interface, such as reduced cable-bulk and cost, faster and more efficient data transfer, full duplex, and hot swapping. It is designed to replace the older ATA (AT Attachment) standard (Parallel ATA). All SATA devices support hot plugging and hot swapping. SATA supports Native Command Queuing (NCQ) for enhanced performance.

SCSI

SCSI Small Computer System Interface (SCSI) is the second most popular drive interface in use today after the Integrated Drive Electronics (IDE) interface. SCSI is faster than IDE and supports more devices. SCSI devices, such as hard disk drive and CD-ROM drive, are better suited in a network environment in which many users access shared drives simultaneously. SCSI has three standards: SCSI-1, SCSI-2, and SCSI-3.

SMTP

SMTP Simple Mail Transfer Protocol (SMTP) is a protocol for sending e-mail messages between servers. E-mailing systems use this protocol to send mails over the Internet. SMTP works on the application layer of the TCP/IP or OSI reference model. The SMTP client typically initiates a Transmission Control Protocol (TCP) connection to the SMTP server on the well-known port designated for SMTP, port number 25. However, e-mail clients require POP or IMAP to retrieve mails from e-mail servers.

SSID

SSID SSID stands for Service Set Identifier. It is used to identify a wireless network. SSIDs are case sensitive text strings and have a maximum length of 32 characters. All wireless devices on a wireless network must have the same SSID in order to communicate with one another. The SSID on computers and the devices in WLAN can be set manually and automatically. Configuring the same SSID as that of the other Wireless Access Points (WAPs) of other networks will create a conflict. A network administrator often uses a public SSID that is set on the access point. The access point broadcasts SSID to all wireless devices within its range. Some newer wireless access points have the ability to disable the automatic SSID broadcast feature in order to improve network security.

SSL

SSL Secure Sockets Layer (SSL) is a protocol that was developed by Netscape for transmitting private documents via the Internet. It uses a cryptographic system that uses public and private keys to encrypt data. The SSL protocol provides communications privacy, authentication, and message integrity. This protocol enables clients and servers to communicate in a manner that prevents eavesdropping and tampering. All major browsers support the SSL protocol. Several Web sites use this protocol to obtain confidential user information. When the SSL protocol is used to connect to a Web site, the URL must begin with https instead of http.

Server

Server A server is a computer system dedicated to running one or more such services (as a host), to serve the needs of users of the other computers on the network. Depending on the computing service that it offers it could be a database server, file server, mail server, print server, web server, or some other kind of servers.

Single Core Processor

Single core processor Single core processor is a processor that has only one core, so it can only start one operation at a time. It can however in some situations start a new operation before the previous one is complete. Originally all processors were single core. Multi core processors were introduced later, when increasing the clock speeds further was too hard. These new multi core processors are more than one processing units combined into a single chip.

Smartphone

Smartphone A smartphone is a mobile phone that has a number of features just like an advanced computer. Smartphones have a special type of operating system that allows a user to connect to devices and also to install applications. Smartphones also have a feature to send and receive emails and also allow web browsing. Some smart phones have few additional features, such as a miniature computer-type keyboard or a touch screen, GPS positioning systems, read documentation, a built-in camera, display photos and video clips, media software for playing music, etc. Smartphones run complete operating system software providing a platform for application developers. Some of the features of a smartphone are as follows: It can be used for accessing a high-speed wireless data network. It can be used to connect a laptop to the Internet. It can be used for instant messaging. A user can also install add-on applications to extend the capabilities of smartphones. A user can receive and place calls easily and quickly. A user can connect to multiple e-mail accounts using a smartphone.

Tuner

Tuner A TV tuner card is a computer component that allows television signals to be received by a computer. There are two types of TV tuner cards: Internal TV tuner card: These types of TV tuner cards are located inside the cabinet of a computer system. External TV tuner card: These types of TV tuner cards are located outside and there is no need to run the CPU at the same time. A TFT/LCD/CRT monitor can be used to fulfill the requirement of television without running the CPU.

USB Storage

USB Storage (solid state vs. magnetic disk) USB Storage solid state devices comprise flash drive, zip drive, and thumb drive, etc. These devices are very small can be kept in pocket. They can hold large amount of data from 2 GB to 64 GB. USB Storage magnetic disk comprises external hard disks. This external hard disk is very useful to hold large amount of data ranging from 250 GB to 2000 GB. These external disk are also portable and can be easily carried from one place to another. Some external hard disk requires power.

Upgrade Issues

Upgrade issues It is very important to upgrade your operating system (open source or commercial) to safeguard the computer system. By upgrading an operating system, a user can also increase the system's performance. After upgradation of an OS, sometimes few application software or utilities or recently installed tools stopped working. It might be possible that newly updated system is not supporting some applications.

Upgrade issues in a computer regarding RAM

Upgrade issues in a computer regarding RAM Defective or Poor quality RAM is a major reason behind system crashes. The type of RAM supported as well as the maximum amount of RAM supported by a motherboard has a direct effect on system's upgradeability.

VOIP

VOIP Voice over Internet Protocol (VoIP) is a general term for a family of transmission technologies for delivery of voice communications over IP networks, such as the Internet or other packet-switched networks. Other terms frequently encountered and synonymous with VoIP are IP telephony, Internet telephony, Voice over Broadband (VoBB), broadband telephony, and broadband phone. VoIP systems employ session control protocols to control the set-up and tear-down of calls as well as audio codecs that encode speech, allowing transmission over an IP network as digital audio via an audio stream.

WAP

WAP The Wireless Access Protocol (WAP) is a technology used with wireless devices. The functionality of WAP is equivalent to that of TCP/IP. WAP uses a smaller version of HTML called Wireless Markup Language (WML) to display Internet sites.

Web Camera

Web Camera Web cameras (webcams) are specialized cameras designed to record live video and transmit it across a network or the Internet. The video can be transmitted live, or recorded and saved for transmission at a later time. Many webcams include built-in microphones, and most include software for video e mail, video capture, videoconferencing, and still-image capture. Most consumer webcams provide VGA-resolution video at 30 frames per second. They capture video at relatively low resolutions, typically one megapixel or less, which is fine for personal and low-end business video. Webcams must be connected to a PC, usually via a USB connection. The PC runs software to capture the video and package it for network-based distribution.

Web Delivered Services

Web delivered services Web delivered services include instant messaging, video calling, video conferencing, tele-conferencing, remote access of computer systems, e-mail communications, etc.

Wireless Router

Wireless router A wireless router is a device that performs the functions of a router but also includes the functions of a wireless access point. It is commonly used to allow access to the Internet or a computer network without the need for a cabled connection. It can function in a wired LAN (local area network), a wireless only LAN or a mixed wired/wireless network.

DVD/DVD-RW Drive

DVD/DVD-RW Drive DVD drive is used for read/write operations on DVDs. The drives that are capable of performing write operations on DVDs are also known as DVD burners. There are many DVD burning technologies, such as DVD+R, DVD+RW, etc. DVD-ROM is a removable optical disc storage media. It is used for data storage, including movies with high quality audio and video. DVD-ROMs look same as CDs, their physical dimensions being the same, but they are encoded in a different format and at a much higher density. A DVD-ROM can store up to 4.3GB of data.