IT lesson 5 and 6

kilobyte (KB)

1,024 bytes.

megabyte (MB)

1,048,576 bytes, or 1,024 kilobytes of 1,024 bytes each.

memory

A "work area" used by the CPU to read and write data and programs quickly while they are being used; primary types are ROM and RAM.

Universal product code (UPC)

A bar pattern used on package or labels of products you buy. The bar code contains a pattern that enables the computer to match the UPC information with the product data stored in the computer (such as a price) and display it on the cash register.

gigahertz (GHz)

A billion cycles per second; a measurement used to express a computer system's clock speed or clock rate.

touch screen

A display screen that is sensitive to the touch of a finger or stylus. Used in myriad applications, including laptops, tablet computers, smartphones, ATM machines, retail point-of-sale terminals, and car navigation.

circuit board

A flat piece of insulating material inside a computer, on which electrical components are mounted.

computer system

A four-part system consisting of hardware, software, data, and people that performs four basic actions: input, output, processing, and storage.

Kiosk

A freestanding input/output device that uses a touch screen for the input of information requests and then displays feedback on the same screen.

byte

A group of eight bits.

megahertz (MHz)

A million cycles per second. This is an older measurement used to express a computer system's clock speed or clock rate; most processors (even those on mobile devices) are in the gigahertz range today.

tablet

A mobile general-purpose computer contained in a single panel. Its distinguishing characteristic is the use of a touch screen as the input device. Modern tablets are operated by fingers, and a stylus is an option. Tablets usually come with a web browser and Wi-Fi networking.

port

A place, often on the back of a desktop or the side of a laptop. Where a connection is made between two devices so that they can work together and exchange information.

trackball

A pointing device that has a ball on the top of the mouse. You move the on-screen pointer by rolling the ball.

inkjet printer

A printer that contains cartridges of liquid ink that is squirted onto the page. (input)

laser printer

A printer that works in a similar manner as copy machines. As the paper is rolled around a drum, toner from the drum is applied to the paper using heat.

bar code reader

A scanning device that scans a bar pattern called a universal product code (UPC).(

software

A set of electronic instructions, also called programs, that tells a computer what to do.

USB (universal serial bus)

A standard input and output connection for many modem peripherals.

random-access memory (RAM)

A type of memory that contains data that can be read or written to but is lost when the computer is turned off.

system clock

An electronic source that generates a steady stream of electronic pulses used to time sequences of actions within the processor.

modem

An input/output device that sends and receives messages through telephone lines.

optical drive

An optical storage device that reads data on optical discs; variations include CD-ROM drives (read-only), CD-R drives (record once, read many times), CD-RW drives (rewritable), and similar forms for DVD and Blu-ray. CDs have a smaller storage capacity than digital video discs (DVDs), which have a smaller storage capacity than Blu-ray.

system board

Another name for the motherboard.

terabyte (TB)

Approximately one trillion bytes, this quantity is 1,0244 bytes or 240. Hard disk drive storage capacity is typically in this range (half a TB to several TB).

Stylus

Many portable computers use special "pens" as input devices. Instead of using ink, this type of pen sends electrical signals through a touch screen. (input device)

Keyboard

Most common type of input device,you can type text, select commands, and move around in a document.

gigabyte (GB)

One billion bytes is the decimal definition used in telecommunications and by most computer storage manufacturers for devices describing main memory capacities. A gigabyte is 1,073,741,824 bytes, equal to 1,0243 or 230.

pixel

One tiny spot in a grid of thousands of spots used to form an image on a computer screen or on paper, combines the words picture and element.

microprocessor

The "brain" of the computer that interprets and executes instructions; also called the central processing unit (CPU).

central processing unit (CPU)

The "brain" of the computer that interprets and executes instructions; also called the microprocessor or processor.

processing

The action(s) a computer takes while following instructions from a software program.

input

The data entered into a computer; also, the action of entering data.

output

The data produced by a computer after processing; also, the action of producing data.

storage devices

The hardware components that read and write data to and from storage media.

motherboard

The main circuit board in a computer that unifies all of a computer's electrical pathways and devices; also called the system board.

hardware

The mechanical or physical devices of a computer system.

storage

The media and devices used to record and hold data and programs permanently

Color depth

The number of colors that a computer monitor can display at one time.

hard drive

The primary, magnetic storage device in a computer. It is made of a group of thin, rigid platters that spin on a central spindle. The disk itself might be made of metal, aluminum, glass, or a form of ceramic.

BIOS (basic input/output system)

The program a CPU uses to start a computer when it is turned on. The BIOS also manages the data transfer to external peripherals.

data

The raw information, including text, numbers, sounds, and images, that a computer reads and stores in the form of numbers.

bit

The smallest unit of data that a computer can use and store, having a value of either 0 or 1. The word is an abbreviation for binary digit.

touchpad

Variations of pointing devices activated by moving your finger around on the pad.

peripheral

a device that is attached to a host computer but is not part of the computer and is more or less dependent on the host computer. Devices used for input and output

Monitor

a hardware device that displays information on a screen. (output)

Combination or multifunction printers

act like a printer, a fax, a scanner, and a copy machine. Multifunction printers are especially designed for small businesses and home offices since they are relatively inexpensive.(output)

Output Device

any piece of hardware that "plays back" the result of computer processing in the form of text, graphics, video, or audio.

Input Device

any piece of hardware that is used to enter data into a computer.

Digital photos

can be transferred to your computer where they can be edited, stored, printed, added to documents, or easily sent to another person.

Digital camera

capture images electronically on special memory disks instead of using film as regular cameras do.

touch screen

combine an LCD monitor for output with a touch-sensitive surface for input. The touch-sensitive surface serves as a type of pointing device.

resolution

measured in pixels;expressed with two numbers: the number of pixels that the monitor can display across the screen (horizontal) and the number of pixels that the monitor can display down the screen (vertical).

Microphone

permit audio input, whether spoken words or ambient sound.

game controller

such as a joystick or gamepad is a special input device used when playing computerized games

Mouse

used to perform tasks such as starting programs, selecting text, and moving and resizing items. Use either optical or laser technology.