bit

noun

Unit 4 — IT Lesson

Definition
The smallest unit of digital information. A single on or off signal. A one or a zero.

Example
A bit is a signal that is either off or on.

byte

noun

Unit 4 — IT Lesson

Definition
Eight bits. The most common unit of measurement for digital information.

Example
A byte is larger than a bit. It takes eight bits to make one byte.

clock speed

noun

Unit 4 — IT Lesson

Definition
A measure of how fast a processor cycles through its work.

Example
A common clock speed is 2.2 GHz. The clock speed often indicates how quickly the processor can cycle through its work.

desktop computer

noun

Unit 4 — IT Lesson

Definition
A personal computer designed to stay in one place, usually on or beside a desk.

Example
The director uses a desktop computer in his office at work and uses a laptop computer when he travels.

expansion card

noun

Unit 4 — IT Lesson

Definition
A computer part that fits into the motherboard to give a computer new capabilities.

Example
The three most common types of expansion cards are sound cards, video cards, and network cards.

graphics adapter

noun

Unit 4 — IT Lesson

Definition
An expansion card that converts digital video into signals for monitors. It is also called a “video card”.

Example
You will need a fast graphics adapter if you want to play video games because there is so much information going to your monitor for you to watch.

hard disk drive

noun

Unit 4 — IT Lesson

Definition
The part of a computer that stores information, such as software or documents, even when the power is off.

Example
Every computer has a hard disk drive. It is the main storage area of a computer.

hardware

noun

Unit 4 — IT Lesson

Definition
The physical parts of a computer (or other digital device).

Example
The hardware on our computer includes a monitor, a hard disk drive, a processor, RAM, a sound card, a printer, and a keyboard.

main memory

noun

Unit 4 — IT Lesson

Definition
The part of a computer that stores information while it is being used or changed by software. Main memory is also called “RAM”.

Example
Computers that have a lot of main memory don’t need to access the hard drive as often when processing information.

motherboard

noun

Unit 4 — IT Lesson

Definition
A large circuit board into which you plug all your other hardware so it can communicate.

Example
Every computer needs a motherboard. It is necessary so that the hardware can work together and run your computer properly.

optical disk drive

noun

Unit 4 — IT Lesson

Definition
The part of a computer that reads CDs or DVDs.

Example
The optical disk drive reads CDs and DVDs by using laser light.

port

noun

Unit 4 — IT Lesson

Definition
An opening, usually in the back of your computer, where you plug in devices such as printers or a mouse.

Example
It is common for a computer to have ports so that you can plug in items such as a printer, mouse, or modem.

processor

noun

Unit 4 — IT Lesson

Definition
The part of a computer that solves the problems sent to it by software.

Example
A faster processor will let your computer solve problems more quickly.

sound card

noun

Unit 4 — IT Lesson

Definition
An expansion card that converts digital sound into signals for speakers or earphones.

Example
You will need a sound card on your computer if you want to listen to the sound on the videos or CDs.