CB-L3

A case containing electronic components of the computer used to process data.

System Unit

The main circuit board of the system unit built on integrated circuit chips.

Motherboard

Interprets and carries out basic instructions that operate a computer.

Processor (CPU)

Directs and coordinates most operations in the computer and interprets instructions.

Control Unit (CU)

Performs arithmetic, comparison, and other operations.

Arithmetic and Logic Unit (ALU)

Four basic operations: fetching, decoding, executing, and storing.

Machine Cycle

A quartz crystal circuit that generates electronic pulses to control operation timing.

System Clock

Digital system recognizing two discrete states (on/off, 1 and 0) using bits.

Binary System

The most widely used coding scheme to represent data using 0s and 1s.

ASCII

Electronic components that store instructions, data, and processing results.

Memory

A unique number that identifies the location of a byte in memory.

Memory Address

Temporary memory that loses its contents when power is turned off (e.g., RAM, cache).

Volatile Memory

Permanent memory that does not lose contents when power is removed (e.g., ROM, flash memory).

Nonvolatile Memory

Read and write main memory; includes DRAM and SRAM.

RAM (Random Access Memory)

Stores frequently used instructions and data to speed up computer processes.

Memory Cache

Chips storing permanent data and instructions, often called firmware.

ROM (Read Only Memory)

Nonvolatile memory that can be erased electronically and rewritten.

Flash Memory

The amount of time it takes the processor to read data, instructions, and information from memory.

Access Time

A circuit board that enhances system unit functions or provides peripheral connections.

Adapter Card

The point at which a peripheral attaches to a system unit to send/receive data.

Port

Connects up to 127 different peripherals with a single connector; includes fast versions like USB 2.0 and 3.0.

USB Port

Uses radio waves to transmit data between two devices within about 11 meters.

Bluetooth Technology

A channel that allows various internal and attached devices to communicate by transferring bits.

Bus

Used to transfer the actual data within computer buses.

Data Bus

Used to transfer information about where data should reside in memory.

Address Bus

Contains lines that carry read or write instructions.

Control Bus

The size of a bus that determines the number of bits transmitted at one time.

Bus Width

An opening inside the system unit in which additional equipment can be installed (external or internal).

Bay

Converts wall outlet AC power into DC power for the motherboard and components.

Power Supply