Computer literacy
Netiquette
"Network etiquette." The unofficial rules of accepted, proper online social conduct The rules for good manners on the Internet
FTP
(File Transfer Protocol) A set of rules for uploading and downloading files between a client computer and a remote server.
six steps in the program development cycle
1 Analyze the problem Precisely define the problem to be solved, and write program specifications - descriptions of the program's inputs, processing, outputs, and user interface. 2 Design the program Develop a detailed logic plan using a tool such as pseudocode, flowcharts, object structure diagrams, or event diagrams to group the program's activities into modules; devise a method of solution or algorithm for each module; and test the solution algorithms. 3 Code the program Translate the design into an application using a programming lanaguage or application development tool by creating the user interface and writing code; include internal documentation - comments and remarks within the code that explain the purpose of code statements. 4 Test and debug the program Test the program, finding and correcting errors (debugging) until it is error free and contains enough safeguards to ensure the desired results. 5 Formalize the solution Review and, if necessary, revise internal documentation; formalise and complete end-user (external) documentation 6 Maintain the program Provide education and support to end users; correct any unanticipated errors that emerge and identify user-requested modifications (enhancements). Once errors or enhancements are identiied, the program development life cycle begins again at Step 1.
URL
A URL is one type of Uniform Resource Identifier (URI); the generic term for all types of names and addresses that refer to objects on the World Wide Web. The term "Web address" is a synonym for a URL that uses the HTTP / HTTPS protocol.
expansion cards
A circuit board inserted into a slot on the motherboard to enhance the capability of the computer.
Keyboard
A common input device through which data and instructions may be typed into computer memory.
Identify possible security risks including computer viruses, data loss, software piracy, and loss of personal privacy
A computer security risk is any event or action that could cause a loss of or damage to computer hardware, software, data, information, or processing capability. Perpetrators of cybercrime and other intrusions fall into seven basic categories: hacker, cracker, script kiddie, corporate spy, unethical employee, cyberextortionist, and cyberterrorist. • The term hacker, although originally a com plimentary word for a computer enthusiast, now has a derogatory meaning and refers to someone who accesses a computer or network illegally. Some hackers claim the intent of their security breaches is to improve security. • A cracker also is someone who accesses a computer or network illegally but has the intent of destroying data, stealing information, or other malicious action. Both hackers and crackers have advanced computer and network skills. • A script kiddie has the same intent as a cracker but does not have the technical skills and knowledge. Script kiddies often use prewritten hacking and cracking programs to break into computers. • Some corporate spies have excellent computer and networking skills and are hired to break into a specific computer and steal its proprietary data and information, or to help identify security risks in their own organization. Unscrupulous companies hire corporate spies, a practice known as corporate espionage, to gain a competitive advantage. • Unethical employees may break into their employers' computers for a variety of reasons. Some simply want to exploit a security weakness. Others seek financial gains from selling confidential information. Disgruntled employees may want revenge. • A cyberextortionist is someone who uses e-mail as a vehicle for extortion. These perpetrators send an organization a threatening e-mail message indicating they will expose confidential information, exploit a security flaw, or launch an attack that will compromise the organization's network — if they are not paid a sum of money. • A cyberterrorist is someone who uses the Internet or network to destroy or damage computers for political reasons. The cyberterrorist might target the nation's air traffic control system, electricity-generating com panies, or a telecommunications infrastructure. The term, cyberwarfare, describes an attack whose goal ranges from disabling a government's computer network to crippling a country. Cyberterrorism and cyberwarfare usually require a team of highly skilled individuals, millions of dollars, and several years of planning. Business and home users must protect, or safeguard, their computers from breaches of security and other computer security risks. Some organizations hire individuals previously convicted of computer crimes to help identify security risks and implement safeguards because these individuals know how criminals attempt to breach security. The more common computer security risks include Internet and network attacks, unauthorized access and use, hardware theft, software theft, information theft, and system failure (Figure 11-1). The following pages describe these computer security risks and also discuss safeguards users might take to minimize or prevent their consequences.
database management
A database management system (DBMS) is a computer program (or more typically, a suite of them) designed to manage a database, a large set of structured data, and run operations on the data requested by numerous users. Typical examples of DBMS use include accounting, human resources and customer support systems.
pointing devices
A device used to enter information into the computer. When you move the pointing device, an arrow appears. You can point and click the arrow on various buttons that appear on the screen. The three types of pointing devices are the mouse, the trackball, and the touch pad.
touch screen
A display that responds to the touch.
Internet
A global network connecting millions of computers, making it possible to exchange information.
LAN
A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, or office building.[1] A local area network is contrasted in principle to a wide area network (WAN), which covers a larger geographic distance and may involve leased telecommunication circuits, while the media for LANs are locally managed.
printer
A peripheral output device that produces printed output to paper. Different types include dot matrix, ink-jet, and laser printers.
P2P file sharing
A practice in which individuals can obtain music, video, and other types of files from other users on a network; sometimes the files are shared without authorization from the copyright holder
Browser
A program that allows the user to find and view pages on the world wide web.
communication protocol
A set of pre-agreed signals, codes and rules to be used for data and information exchange between computers, or a computer and a peripheral device such as a printer, that ensure that the communication is successful.
WAN
A wide area network (WAN) is a telecommunications network or computer network that extends over a large geographical distance. Wide area networks often are established with leased telecommunication circuits.
CPU
Abbreviation of central processing unit. The CPU is the brains of the computer. Sometimes referred to simply as the processor or central processor, the CPU is where most calculations take place.
Instant messaging
An online mechanism or a form of real-time communication among two or more people based on typed text or multimedia data. The text is conveyed via computers or another electronic device (e.g cell phone or handheld device) connected over a network, such as the Internet.
Name and purpose of utility programs
Anti-virus utilities scan for computer viruses. Archivers output a stream or a single file when provided with a directory or a set of files. Archive utilities, unlike archive suites, usually do not include compression or encryption capabilities. Some archive utilities may even have a separate un-archive utility for the reverse operation. Backup software can make copies of all information stored on a disk and restore either the entire disk (e.g. in an event of disk failure) or selected files (e.g. in an event of accidental deletion). Clipboard managers expand the clipboard functionality of an operating system . Cryptographic utilities encrypt and decrypt streams and files. Data compression utilities output a shorter stream or a smaller file when provided with a stream or file. Data synchronization utilities establish consistency among data from a source to a target data storage and vice versa. There are several branches of this type of utility: File synchronization utilities maintain consistency between two sources. They may be used to create redundancy or backup copies but are also used to help users carry their digital music, photos and video in their mobile devices. Revision control utilities are intended to deal with situations where more than one user attempts to simultaneously modify the same file. Debuggers are used to test and "debug" other programs, mainly to solve programming errors. Also utilized for reverse engineering of software or systems. Disk checkers can scan operating hard drive. Disk cleaners can find files that are unnecessary to computer operation, or take up considerable amounts of space. Disk cleaner helps the user to decide what to delete when their hard disk is full. Disk compression utilities can transparently compress/uncompress the contents of a disk, increasing the capacity of the disk. Disk defragmenters can detect computer files whose contents are scattered across several locations on the hard disk, and move the fragments to one location to increase efficiency. Disk partitions can divide an individual drive into multiple logical drives, each with its own file system which can be mounted by the operating system and treated as an individual drive. Disk space analyzers for the visualization of disk space usage by getting the size for each folder (including sub folders) & files in folder or drive. showing the distribution of the used space. Disk storage utilities File managers provide a convenient method of performing routine data management, email recovery and management tasks, such as deleting, renaming, cataloging, uncataloging, moving, copying, merging, generating and modifying data sets. Hex editors directly modify the text or data of a file. These files could be data or an actual program. Memory testers check for memory failures. Network utilities analyze the computer's network connectivity, configure network settings, check data transfer or log events. Package managers are used to configure, install or keep up to date other software on a computer. Registry cleaners clean and optimize the Windows Registry by removing old registry keys that are no longer in use. Screensavers were desired to prevent phosphor burn-in on CRT and plasma computer monitors by blanking the screen or filling it with moving images or patterns when the computer is not in use. Contemporary screensavers are used primarily for entertainment or security. System monitors for monitoring resources and performance in a computer system. System profilers provide detailed information about the software installed and hardware attached to the computer.
Backdoor
Back Doors A back door is a program or set of instructions in a program that allow users to bypass security controls when accessing a program, computer, or network. Once perpetrators gain access to unsecure computers, they often install a back door or modify an existing program to include a back door, which allows them to continue to access the computer remotely without the user's knowledge. A rootkit can be a back door. Some worms leave back doors, which have been used to spread other worms or to distribute junk e-mail from the unsuspecting victim computers. Programmers often build back doors into programs during system development. These back doors save development time because the programmer can bypass security controls while writing and testing programs. Similarly, a computer repair technician may install a back door while troubleshooting problems on a computer. If a programmer or computer repair technician fails to remove a back door, a perpetrator could use the back
backup system
Backups have two distinct purposes. The primary purpose is to recover data after its loss, be it by data deletion or corruption. Data loss can be a common experience of computer users. A 2008 survey found that 66% of respondents had lost files on their home PC.[2] The secondary purpose of backups is to recover data from an earlier time, according to a user-defined data retention policy, typically configured within a backup application for how long copies of data are required. Though backups popularly represent a simple form of disaster recovery, and should be part of a disaster recovery plan, by themselves, backups should not alone be considered disaster recovery.[3] One reason for this is that not all backup systems or backup applications are able to reconstitute a computer system or other complex configurations such as a computer cluster, active directory servers, or a database server, by restoring only data from a backup. Since a backup system contains at least one copy of all data worth saving, the data storage requirements can be significant. Organizing this storage space and managing the backup process can be a complicated undertaking. A data repository model can be used to provide structure to the storage. Nowadays, there are many different types of data storage devices that are useful for making backups. There are also many different ways in which these devices can be arranged to provide geographic redundancy, data security, and portability.
Describe how computer processes and stores data
Before data is processed by a computer, it has to be fed into the computer using a keyboard, mouse or another input device. The central processing unit (CPU) analyzes the raw data and processes it into sensible information. The CPU receives instructions from the user and issues prompts accordingly. After the data is processed, it is translated to output formats that are easily understandable by the user The processed data is displayed on the computer for editing, viewing or playing. The computer's CPU then receives instructions from the user to save the data securely on the hard drive. Later, the user can choose to modify, copy, move, edit or delete the data. Some of the output values that data is converted into are documents, video files and audio files. A computer system is comprised of three main parts: hardware, software and users. All components connected to the computer via cable or wireless access point are hardware. These are primarily the tangible parts that include the CPU, monitor, keyboard and mouse. In addition, machines such as printers and scanners are considered part of the computer's hardware. Software consists of the computer applications installed on the computer and used to execute functions. Users are the people who provide instructions to the computer.
Online storage
Cloud storage is a model of data storage where the digital data is stored in logical pools, the physical storage spans multiple servers (and often locations), and the physical environment is typically owned and managed by a hosting company. These cloud storage providers are responsible for keeping the data available and accessible, and the physical environment protected and running. People and organizations buy or lease storage capacity from the providers to store user, organization, or application data. Cloud storage services may be accessed through a co-located cloud computer service, a web service application programming interface (API) or by applications that utilize the API, such as cloud desktop storage, a cloud storage gateway or Web-based content management systems.
data loss
Data loss is an error condition in information systems in which information is destroyed by failures or neglect in storage, transmission, or processing. Information systems implement backup and disaster recovery equipment and processes to prevent data loss or restore lost data.
DoS
Denial of Service Attacks A denial of service attack, or DoS attack, is an assault whose purpose is to disrupt computer access to an Internet service such as the Web or e-mail. Perpetrators carry out a DoS attack in a variety of ways. For example, they may use an unsuspecting computer to send an influx of confusing data messages or useless traffic to a computer network. The victim computer network slows down considerably and eventually becomes unresponsive or unavailable, blocking legitimate visitors from accessing the network. A more devastating type of DoS attack is the DDoS (distributed DoS) attack, in which a zombie army is used to attack computers or computer networks. DDoS attacks have been able to stop operations temporarily at numerous Web sites, including powerhouses such as Yahoo!, eBay, Amazon.com, and CNN.com. Read Ethics & Issues 11-1 for a related discussion. The damage caused by a DoS or DDoS attack usually is extensive. During the outage, retailers lose sales from customers, news sites and search engines lose revenue from advertisers, and time-sensitive information may be delayed. Repeated attacks could tarnish reputations, causing even greater losses. Perpetrators have a variety of motives for carrying out a DoS or DDoS attack. Those who disagree with the beliefs or actions of a particular organization claim political anger motivates their attacks. Some perpetrators use the attack as a vehicle for extortion. Others simply want the recognition, even though it is negative.
Electronic mail An electronic form of communication.
Requirement of enterprise computing
Enterprise Computing is the world of computing and data management in large businesses, industries, and other organizations. While other forms of computing are used extensively in various business capacities, mainframe computers play a central role in the daily operations of most of the world's largest corporations, including many Fortune 1000 companies. In banking, finance, health care, insurance, public utilities, government, and a multitude of other public and private enterprises, the mainframe computer continues to form the foundation of business in today's e-business environment. From processing stock exchange transactions to managing the inventory and supply chains of some of the world's largest retailers, enterprise systems work behind the scenes to keep high volume, large-scale critical operations functioning smoothly and efficiently. Mainframe computers have been the most stable, secure, and compatible of all computing platforms. The latest models can handle the most advanced and demanding customer workloads, yet continue to run applications that were written in the 1970s or earlier. Skilled computer professionals with a good understanding of enterprise computing and experience with IBM System z are needed to develop enterprise system applications for multi-national organizations. Our goal in the enterprise computing area is to give students strong foundation in mainframe computing in general and IBM's z/OS system in particular. Mainframe teaching has been a major strength of NIU's computer science curriculum from its very inception. With our rigorous training in this area our graduates are happily hired by several large corporations nationwide and have excelled in their profession. With our offer of enterprise computing area we hope to retain and enhance this strength NIU enjoyed for many years. Since most large organizations do use mainframes as part of their overall computing environment, this is wholly appropriate and valuable. It is predicted that in the next decade, many mainframe-related jobs will need to be filled, and NIU graduates should be positioned well for this job market. At the same time, it is unlikely that anyone will be working exclusively with a mainframe--or exclusively with UNIX or any single platform. The goal of this area is to prepare our students to be versatile and adaptable and to have the background to thrive in the overall enterprise.
Computer Viruses, Worms, Trojan Horses, and Rootkits
Every unprotected computer is susceptible to the first type of computer security risk — a computer virus, worm, Trojan horse, and/or rootkit. • A computer virus is a potentially damaging computer program that affects, or infects, a computer negatively by altering the way the computer works without the user's knowledge or permission. Once the virus infects the computer, it can spread throughout and may damage files and system software, including the operating system. • A worm is a program that copies itself repeatedly, for example in memory or on a network, using up resources and possibly shutting down the computer or network. • A Trojan horse (named after the Greek myth) is a program that hides within or looks like a legitimate program. A certain condition or action usually triggers the Trojan horse. Unlike a virus or worm, a Trojan horse does not replicate itself to other computers. • A rootkit is a program that hides in a computer and allows someone from a remote location to take full control of the computer. Once the rootkit is installed, the rootkit author can execute programs, change settings, monitor activity, and access files on the remote computer. Although rootkits can have legitimate uses, such as in law enforcement, their use in nefarious and illegal activities is growing rapidly. Computer viruses, worms, Trojan horses, and rootkits are classified as malware (short for malicious software), which are programs that act without a user's knowledge and deliberately alter the computer's operations. Other classes of malware include back doors and spyware, which are discussed later in this chapter. Although malware often falls in one of these classes (virus, worm, Trojan horse, rootkit, back door, or spyware), some malware has characteristics of two or more classes. For example, MyDoom and Blaster are worms; Melissa has elements of a virus, worm, and Trojan horse. Unscrupulous programmers write malware and then test it to ensure it can deliver its payload. The payload is the destructive event or prank the program is intended to deliver. A computer infected by a virus, worm, Trojan horse, or rootkit often has one or more of the following symptoms: • Operating system runs much slower than usual • Available memory is less than expected • Files become corrupted • Screen displays unusual message or image • Music or unusual sound plays randomly • Existing programs and files disappear • Programs or files do not work properly • Unknown programs or files mysteriously appear • System properties change • Operating system does not start up • Operating system shuts down unexpectedly Malware delivers its payload on a computer in a variety of ways: when a user (1) opens an infected file, (2) runs an infected program, (3) boots the computer with infected removable media inserted in a drive or plugged in a port, (4) connects an unprotected computer to a network, or (5) when a certain condition or event occurs, such as the computer's clock changing to a specific date. Today, a common way computers become infected with viruses and other malware is through users opening infected e-mail attachments (Figure 11-3). Currently, more than 300,000 Web sites can infect your computer with known viruses, worms, Trojan horses, rootkits, and other malware. Many Web sites maintain lists of all known malware
advantages of using a network
File Sharing: Networks offer a quick and easy way to share files directly. Instead of using a disk or USB key to carry files from one computer or office to another, you can share files directly using a network. Software Cost and Management: Many popular software products are available for networks at a substantial savings in comparison to buying individually licensed copied for all of your computers. You can also load software on only the file server which saves time compared to installing and tracking files on independent computers. Upgrades are also easier because changes only have to be done once on the file server instead of on individual workstations. Security: Specific directories can be password protected to limit access to authorized users. Also, files and programs on a network can be designated as "copy inhibit" so you don't have to worry about the illegal copying of programs. Resource Sharing: All computers in the network can share resources such as printers, fax machines, modems, and scanners. Communication: Even outside of the internet, those on the network can communicate with each other via electronic mail over the network system. When connected to the internet, network users can communicate with people around the world via the network. Flexible Access: Networks allow their users to access files from computers throughout the network. This means that a user can begin work on a project on one computer and finish up on another. Multiple users can also collaborate on the same project through the network. Workgroup Computing: Workgroup software like Microsoft BackOffice enables many users to contribute to a document concurrently. This allows for interactive teamwork.
communications devices
Hardware that is capable of transferring items to and from computers and devices
start up process of a personal computer
In order for a computer to successfully boot, its BIOS, operating system and hardware components must all be working properly; failure of any one of these three elements will likely result in a failed boot sequence. When the computer's power is first turned on, the CPU initializes itself, which is triggered by a series of clock ticks generated by the system clock. Part of the CPU's initialization is to look to the system's ROM BIOS for its first instruction in the startup program. The ROM BIOS stores the first instruction, which is the instruction to run the power-on self test (POST), in a predetermined memory address. POST begins by checking the BIOS chip and then tests CMOS RAM. If the POST does not detect a battery failure, it then continues to initialize the CPU, checking the inventoried hardware devices (such as the video card), secondary storage devices, such as hard drives and floppy drives, ports and other hardware devices, such as the keyboard and mouse, to ensure they are functioning properly. Once the POST has determined that all components are functioning properly and the CPU has successfully initialized, the BIOS looks for an OS to load. The BIOS typically looks to the CMOS chip to tell it where to find the OS, and in most PCs, the OS loads from the C drive on the hard drive even though the BIOS has the capability to load the OS from a floppy disk, CD or ZIP drive. The order of drives that the CMOS looks to in order to locate the OS is called the boot sequence, which can be changed by altering the CMOS setup. Looking to the appropriate boot drive, the BIOS will first encounter the boot record, which tells it where to find the beginning of the OS and the subsequent program file that will initialize the OS. Once the OS initializes, the BIOS copies its files into memory and the OS basically takes over control of the boot process. Now in control, the OS performs another inventory of the system's memory and memory availability (which the BIOS already checked) and loads the device drivers that it needs to control the peripheral devices, such as a printer, scanner, optical drive, mouse and keyboard. This is the final stage in the boot process, after which the user can access the system's applications to perform tasks.
government regulations which address the storage and disclosure of personal data
In the US, there is no single, comprehensive federal (national) law regulating the collection and use of personal data. Instead, the US has a patchwork system of federal and state laws, and regulations that can sometimes overlap, dovetail and contradict one another. In addition, there are many guidelines, developed by governmental agencies and industry groups that do not have the force of law, but are part of self-regulatory guidelines and frameworks that are considered "best practices". These self-regulatory frameworks have accountability and enforcement components that are increasingly being used as a tool for enforcement by regulators, like the Federal Trade Commission (FTC). The proliferation of security breaches in recent years has led to an expansion of this patchwork system of privacy laws, regulations and guidelines which is becoming one of the fastest growing areas of legal regulation. The combination of an increase in interstate and cross-border data flow, together with the increased enactment of data protection related statutes heightens the risk of privacy violations and creates a significant challenge for a data controller to negotiate the onerous and often inconsistent requirements for each state, when operating at a national level.
privacy issues
Issues include cyberstalking, location disclosure, social profiling, 3rd party personal information disclosure, and government use of social network websites in investigations without the safeguard of a search warrant.
MFDs
Multi-function device, an office all-in-one device (copier, printer, scanner) Multi-function display, an interactive system for presenting various information
I/O devices
PURPOSE AND FUNCTION
strong password
Password strength is a measure of the effectiveness of a password in resisting guessing and brute-force attacks. In its usual form, it estimates how many trials an attacker who does not have direct access to the password would need, on average, to guess it correctly. The strength of a password is a function of length, complexity, and unpredictability.[1] Using strong passwords lowers overall risk of a security breach, but strong passwords do not replace the need for other effective security controls. The effectiveness of a password of a given strength is strongly determined by the design and implementation of the factors (knowledge, ownership, inherence).
phishing attempts
Phishing is the attempt to acquire sensitive information such as usernames, passwords, and credit card details (and sometimes, indirectly, money), often for malicious reasons, by masquerading as a trustworthy entity in an electronic communication.[1][2] The word is a neologism created as a homophone of fishing due to the similarity of using fake bait in an attempt to catch a victim. Communications purporting to be from popular social web sites, auction sites, banks, online payment processors or IT administrators are commonly used to lure unsuspecting victims. Phishing emails may contain links to websites that are infected with malware.[3] Phishing is typically carried out by email spoofing[4] or instant messaging,[5] and it often directs users to enter details at a fake website whose look and feel are almost identical to the legitimate one. Phishing is an example of social engineering techniques used to deceive users,[6] and exploits the poor usability of current web security technologies.[7] Attempts to deal with the growing number of reported phishing incidents include legislation, user training, public awareness, and technical security measures. Many websites have now created secondary tools for applications, like maps for games, but they should be clearly marked as to who wrote them, and users should not use the same passwords anywhere on the internet. Phishing is a continual threat that keeps growing to this day. The risk grows even larger in social media such as Facebook, Twitter, and Google+ for example Hackers create clone of Facebook site and tells you to enter your password and it will be emailed to him. This is called Facebook Phishing. Hackers commonly take advantage of these sites to attack people using them at their workplace, homes, or in public in order to take personal and security information that can affect the user or company (if in a workplace environment). Phishing takes advantage of the trust that the user may have since the user may not be able to tell that the site being visited, or program being used, is not real; therefore, when this occurs, the hacker has the chance to gain the personal information of the targeted user, such as passwords, usernames, security codes, and credit card numbers, among other things
communication software
Programs that 1. Help users establish a connection to another computer or network. 2 manage the transmission of data, instructions, and information. 3. Provide an interface for users to communicate with one another.
Basic rules of netiquette
Rule 1: Remember the Human Rule 2: Adhere to the same standards of behavior online that you follow in real life Rule 3: Know where you are in cyberspace Rule 4: Respect other people's time and bandwidth Rule 5: Make yourself look good online Rule 6: Share expert knowledge Rule 7: Help keep flame wars under control Rule 8: Respect other people's privacy Rule 9: Don't abuse your power Rule 10: Be forgiving of other people's mistakes
Various types of secondary data storage and list the benefits, limitations, and care of each
Secondary storage, sometimes called auxiliary storage or external storage, is non-volatile storage that is not under the direct control of a computer's central processing unit (CPU) or does not directly interact with an application. Typically, secondary storage is used to back up primary storage through replication or other data protection methods, which involves holding a secondary copy of the data. In a business environment, an older network-attached storage (NAS) box, storage-area network (SAN) or tape library may be used for secondary storage. Object storage devices can also be used to implement secondary storage and lessen the demand on primary storage arrays. The growth of corporate data has prompted many storage managers to move data to secondary storage to ease the strain on primary storage systems to reclaim more expensive storage arrays and maintain older data in an easily accessible form to satisfy business and regulatory compliance requirements. The data in secondary storage may not be as current as the data in primary storage, especially when backups are not policy-driven or automated. Secondary storage can also refer to data that is less frequently accessed than primary or production data. Because it is accessed less frequently, it can be migrated to secondary storage devices that perform at a lower level than primary storage and are less expensive. For many companies, placing a second class of storage between primary storage and archival storage is the first step toward a tiered storage environment. Computer storage is made up of primary and secondary storage. Primary storage typically refers to random access memory (RAM) placed near the computer's CPU to reduce the amount of time it takes to move data between the storage and CPU. Secondary storage (sometimes referred to as secondary memory) is at the lower level of the storage hierarchy. It commonly refers to hard disk drives (HDDs), solid-state drive (SSD) storage (flash) or other types of storage devices. Computers use primary and secondary storage for a number of reasons: RAM-based storage is volatile. This means RAM contents are not kept when the power is turned off. In contrast, non-volatile storage devices such as HDDs and SSDs retain their contents even without power. RAM is far more expensive than non-volatile storage on a cost-per-gigabyte basis. The tradeoff is that primary storage (RAM) is much faster than secondary storage. A combination of primary and secondary data allows the computer to take advantage of high-speed, low-capacity, volatile storage and high-capacity, relatively low-speed, non-volatile storage. Definition 3: When primary storage refers to local disks installed inside the server's chassis or to disks in an external storage array, secondary storage may refer to offline or remote storage (such as optical media, a backup tape or a remote archive). Secondary storage typically provides high capacity, but the data may not be immediately accessible. A backup server, for example, may contain vast quantities of data, but the data set is only accessible through dedicated backup software, not through file-level read operations. Similarly, secondary storage media such as optical disks and backup tapes must be mounted before they can be read. Definition 4: Secondary storage can also refer to cloud storage. This is especially true when cloud storage is used for data archiving. Many organizations find cloud-based archives to be a more cost-effective way to store aging, relatively static data than locally on a server's primary storage.
Social engineering
Social engineering is a non-technical method of intrusion hackers use that relies heavily on human interaction and often involves tricking people into breaking normal security procedures. It is one of the greatest threats that organizations today encounter.
software piracy
Software piracy (the illegal copying of software programs) is a worldwide problem — more than $11 billion is lost to piracy every year. Because software is valuable, and it is easy to create an exact copy of a program from a single computer, software piracy is widespread.
categories of software
System software and application software Operating system
Major components of URL
The basic components in a URL are: http: //www.website.com /products/ laptop.html protocol server name directory name page or file name 1) Protocol comes first and ends with a colon eg. http: 2) Server name comes then, prefixed with a double slash eg. //www.website.com Server name further divided into: a) Server's name eg. www b) Domain name eg. website.com 3) Directory which comes next with slashes before and after eg. /products/ 4) Actual Page / file name comes last eg. laptop.html
ports
The physical input/output interfaces to the networking hardware
File sharing
The process of allowing access to document, photo, video, and other files from a computer other than the one on which they are stored
system development cycle and identify key players in the cycle
The systems development life cycle (SDLC), also referred to as the application development life-cycle, is a term used in systems engineering, information systems and software engineering to describe a process for planning, creating, testing, and deploying an information system.[1] The systems development life-cycle concept applies to a range of hardware and software configurations, as a system can be composed of hardware only, software only, or a combination of both.[2]
categories of computer users
The vast majority of computer users are application-oriented The second largest group consists of goal-oriented users The third and smallest group of computer users — ironically, the original computer users — is comprised of hackers
data projectors
These can project a computer screen onto a large interactive whiteboard.
purpose of an operating system
To allow a user or application program to access the hardware
Web browser
To look at information on the web you must use a special program e.g. Safari or Internet Explorer
Popular operating system
UNIX Microsoft windows and Macintosh system (Mac OS) AIX (Advanced Interactive eXecutive) - a proprietary (i.e., commercial) flavor (i.e., variant) of UNIX launched by IBM in 1990 for use on its mainframe computers. Amiga - launched with the pioneering Amiga personal computer in 1985 and continues to be developed today for the PowerPC processor. Amiga features an elegant GUI (graphical user interface) together with some of the flexibility of Unix-like operating systems. BeOS - developed by Be Incorporated in 1990 as a media operating system that was optimized for digital media (e.g., digital audio, digital video and three-dimensional graphics). BeOS has some Unix-like characteristics, including its use of the bash (the default on Linux) command shell and its directory structure, but it was written in entirely new code. The loyal user base was very disappointed when the company failed commercially, and thus several open source projects, including beunited.org, are under way that are aimed at recreating and updating (e.g., new video drivers) BeOS. Darwin - an open source derivative of 4.4BSD1 (Berkeley Software Distribution Version 4.4) that serves as the core for the Macintosh OS X. It was originally released in March 1999. There is also a GNU version of Darwin, which is called GNU-Darwin. FreeBSD - the most popular of the BSD operating systems, accounting for approximately 80 percent of BSD installations (at least until Darwin came onto the scene). FreeBSD was begun in early 1993 based on 4.3BSD, and the first version, 1.0, was released in December of that year. FreeDOS - begun in 1994 by Jim Hall with the goal of becoming a complete, free and fully MS-DOS compatible operating system for x86 (i.e., Intel-compatible) CPUs (i.e., central processing units). GNU/Hurd - has been under development by Richard Stallman and his Free Software Foundation (FSF) since 1990. The core component, the Hurd (Hird of Unix-replacing daemons) kernel (i.e., the core of the operating system), is still not completed because of its very ambitious goal: to surpass Unix-like kernels in functionality, security and stability while remaining largely compatible with them. HP-UX - a proprietary flavor of UNIX developed by Hewlett-Packard for its HP 9000 series of business servers. HP-UX 1.0 was released in 1986. IRIX - a proprietary flavor of UNIX introduced by Silicon Graphics, Incorporated (SGI) in 1982 for applications that use three dimensional visualization and virtual reality. JavaOS - developed by Sun Microsystems in 1996 for use in embedded systems (i.e., combinations of circuitry and software built into other products). JavaOS is written primarily in the Java programming language and includes a Java virtual machine (which allows running of any Java program regardless of the type of CPU used) as a fundamental component. Linux - a high performance, yet completely free, Unix-like operating system launched by Linus Torvalds in 1991. GNU/Linux, as it is also called (because it makes extensive use of utilities and other software developed by the GNU project) is suitable for use on a wide range of platforms and is compatible with both 32 bit and 64 bit processors. More than 200 distributions (i.e., versions) of Linux have been introduced, among the most popular of which are Red Hat, SuSE, Mandrake, Debian and Ubuntu. Although its overall market share is still small, Linux is the most rapidly growing of any major operating system. Mac OS X - was released by Apple Computer, Inc. in 2001 as a replacement for its aging Mac OS operating system. Now commonly referred to as Mac Classic, the pioneering Mac OS was introduced with the first Macintosh computers in 1984, and it was the first commercial operating system to include a GUI. Mac OS X was developed as an entirely new, BSD-based operating system that runs on a more advanced processor (the PowerPC) but which maintains backward compatibility with the Mac OS (which runs on the Motorola m68k). The Mac OS X consists of Darwin and the Mach microkernel (an advanced kernel developed at Carnegie-Mellon University) together with Apple's proprietary Aqua GUI (which is widely regarded as the best in the industry). Apple is currently completing a transition of its hardware and OS X from the PowerPC to x86 processors. Microsoft Windows - the successors to the very popular MS-DOS, it was announced in 1983, and the first version, Windows 1.0, was finally released in 1985. Microsoft Windows encompasses two groups of operating systems (i.e., Windows 95/98/ME/CE and Windows NT/2000/XP) which resemble each other superficially and share compatibility with many of the same application programs but which have very different internal structures. MINIX - a small, open source UNIX clone that was first released in January 1987. It was written for use in computer science education by Professor Andrew S. Tanenbaum of Vrije Universiteit in Amsterdam, and it is now best known for its role in inspiring Linus Torvalds to develop Linux. MS-DOS - a single-user, single-tasking operating system that uses a command line (i.e., text only) user interface. It was launched by Microsoft in 1981 and used on the first personal computers, which were introduced by IBM in the same year. In spite of its very small size and relative simplicity, MS-DOS is one of the most successful operating systems that has been developed to date. NetBSD - a derivative of 4.3BSD and launched in 1993, as was the case with FreeBSD. It is possibly the most portable of all operating systems, with the ability to run on more than 50 processors, ranging from the acorn26 to the x86. OpenBSD - spun off from NetBSD in 1996 by Theo de Raadt in Calgary, Alberta because of a desire to place even more emphasis on security. OpenBSD has a goal of becoming the most secure operating system, and it claims to have had only one remote hole in the default install in more than eight years. Palm OS - developed by PalmSource, Inc. for personal digital assistants (PDAs). Palm OS features flexibility and ease of use. It is the leading PDA operating system, used in more than 36 million mobile devices, and there are more than 20,000 software titles for it, far more than for any other handheld platform. QNX - a Unix-like, POSIX-compliant2, real time operating system developed in 1982 that is widely used for mission- and life-critical embedded applications. QNX can also be used as a desktop operating system and features a unique and attractive GUI. Although it is a commercial operating system owned by QNX Software Systems in Ontario, Canada, it is free for personal use. SkyOS - a commercial hobbyist operating system developed by Robert Szeleney from 1996. SkyOS has some features that resemble BeOS. It is mostly POSIX compliant, and comes with many of the GNU utilities, including the very highly rated GCC (GNU Compiler Collection). Solaris - developed by Sun Microsystems for its SPARC processor and the most widely used proprietary flavor of UNIX. Solaris was introduced as SunOS in 1989, and it was based on BSD Unix. A version for x86 processors is also available. TRON (The Real-time Operating system Nucleus) - started by Professor Ken Sakamura of the University of Tokyo in 1984 with the goal of creating an ideal computer architecture. TRON claims to be the world's most widely used operating system because it is embedded in a vast number and variety of electronic products. The TRON specifications are open, but there is no requirement to make source code (i.e., the human-readable form in which the software is originally written) freely available, in contrast to the GPL3. Tru64 - a proprietary flavor of UNIX offered by Hewlett-Packard for the 64-bit Alpha processor. It is unusual among Unix-like operating systems in that it is built on the Mach kernel, which is also used in Mac OS X. Tru64 was originally developed by Digital Equipment Corporation (DEC) and called Digital UNIX.
E-commerce
Web-based economic activities
Chat rooms
Websites or services that allow many users to share information via text. Google text is an example.
media cards
What are some examples of Storage Devices
set macro security setting and understand how a macro virus spreads
With few exceptions, macro viruses are spread when a user opens or closes an infected document. Documents are spread between users in the following ways: email, diskette, Internet, and CD-ROM.
WWW
World Wide Web; a system of interlinked hypertext documents contained on the internet
expansion slot
a long skinny socket on the motherboard into which you insert an expansion card.
Intranet
a network designed for the exclusive use of computer users within an organization that cannot be accessed by users outside the organization
biometric readers
are used to input data about a person into a computer system so that the individual can be identified based on a particular unique physiological characteristic.
buses
bus is the term used for a set of wires connecting the processor to other parts of the computer (address bus, data bus , control bus)
monitor
display consisting of a device that takes signals from a computer and displays them on a CRT screen
Purpose of encryption
encryption is a way to send a message in code. The only person who can decode the message is the person with the correct key; to anyone else, the message looks like a random series of letters, numbers, and characters. Encryption is especially important if you are trying to send sensitive information that other people should not be able to access. Because email messages are sent over the internet and might be intercepted by an attacker, it is important to add an additional layer of security to sensitive information. How does encryption work? Obtain the public key for the person you want to be able to read the information. If you get the key from a public key ring, contact the person directly to confirm that the series of letters and numbers associated with the key is the correct fingerprint. Encrypt the email message using their public key. Most email clients have a feature to easily perform this task. When the person receives the message, he or she will be able to decrypt it.
Computer literacy
knowledge of computer systems and equipment and the ways they function; it includes the knowledge of equipment and devices (hardware), programs (software), databases, and telecommunications
ocr
optical character recognition
categories of computers
personal computers, mobile devices and computers, game consoles, servers, mainframes, supercomputers, and embedded computers
voice input
process of entering input by speaking into a microphone
Virtual reality
replicates an environment that simulates physical presence in places in the real world or imagined worlds and lets the user interact in that world. Virtual reality artificially creates sensory experiences, which can include sight, hearing, touch, and smell.
system software
software responsible for the general operation of a computer system, including the operation of hardware, running application software, and file management The set of programs that enables a computer's hardware devices and application software to work together; it includes the operating system and utility programs.
Spyware
software that enables a user to obtain covert information about another's computer activities by transmitting data covertly from their hard drive.
