The Journey Inside the Computer

bit

A binary digit, a 0 or a 1.

GIF

A format for pictures that many browsers can display developed by CompuServe*

JPEG

A format for storing high-quality color and grayscale photographs in bitmap form. These files are most effective for photographic images or images with lots of subtle color and tones.

arithmetic logic unit

The portion of the microprocessor used for numerical and logical calculations.

software

The programs and data that make computer hardware function.

ASCII

(Pronounced ass-key). An agreed method for pairing the alphanumeric character set with binary representations used in computers.

read only memory (ROM)

A system's permanent, stored instructions, which are never changed; it holds its contents even when the power is turned off.

binary

Anything that has only two states such as on/off or yes/no.

hard drive

The main device that a computer uses to store information.

BMP

A Windows format for a bitmapped graphics file.

artificial intelligence

A branch of computer science which tries to simulate aspects of human intelligence, including the ability to learn from experience and to use reason to solve a problem or respond to a new situation.

embedded

A chip designed with a specific set of usable instructions.

integrated circuit

A complete circuit on a chip, built by a chip fabrication process.

removable media

A portable device allowing for the storage of computer data. Examples can include, Memory Sticks, magnetic tapes, CD-ROM, and DVD R.

transistor

A type of switch that contains no moving parts and uses electricity to turn itself on and off.

micron

A unit of measure that is one millionth of a meter; synonymous with micrometer.

electronic

Adjective for describing a device or result that is dependent on the action of electrons to work.

chip

An integrated circuit. A thin piece of silicon that contains all the components of an electronic circuit.

information processing

Capturing, storing, updating, and retrieving data and information. A computer is an information-processing machine.

storage

In computing, any device in which (or on which) information is stored.

optical disc

Optical disks are used to store computer or media data. Common formats include CD-ROM, CD RW, DVD, HD-DVD and Blu-ray. Optical drives use laser light to read the data stored on optical disks.

pixel

Short for picture element. A pixel is the smallest logical unit of visual information that can be used to build an image. Pixels are the little squares that can be seen when a graphics image is enlarged.

CPU (central processing unit)

The ""brain"" of the computer that performs most computing tasks. In microcomputers, the entire CPU is on a single chip. Also called a processor

control unit

The circuits on the microprocessor that tell the microprocessor to carry out the instructions and control the timing of the instructions.

output

The computer-generated information that is displayed to the user in some form such as a screen display, printed page, or sound.

input

The data that is entered into a computer. The act of entering data into a computer.

microprocessor

The main processing unit of a computer or information processing device; the ""brains"" of the machine carrying out instructions, performing calculations, and interacting with the components used to operate the computer.

processing

The manipulation of data by a microprocessor or embedded processor according to instructions given to it by a program or embedded in the chip itself.

random access memory (RAM)

The memory that is available on a computer for storing data and programs currently being processed. It is automatically erased when the power is turned off

hardware

The physical parts of the computer system that you can touch and feel such as the keyboard, monitor, and computer case.

fetch

The portion of the microprocessor dedicated to requesting and receiving instructions.

execute

To carry out an instruction after it has been decoded.

download

To transfer files or data from one computer to another. To download means to receive; to upload means to transmit.

decode

Translation of information from a code into a form that has meaning to the microprocessor.