| A | B |
|---|
| ABC Computer | The first electronic digital computer. It used vacuum tubes and binary code. |
| binary code | A sequence of 1s and 0s used to give instructions to computers. Also called base-2. |
| central processing unit (CPU) | The "brain" of the computer |
| computer memory | The part of a computer system that stores data so that the computer can use it again when it is needed. |
| computer program | A list of instructions that a computer can follow to carry out a task. Also called software. |
| electronic | A term used to describe a device whose parts are connected by electrical wires. |
| gigahertz (GHz) | Billions of cycles per second. One way of measuring the speed of a microprocessor. |
| integrated circuit (IC) | A tiny piece of silicon with electronic circuits etched into it. Also called a chip. |
| mainframe | A large computer designed to be used by many people at the same time. Commonly used by businesses and universities. |
| microprocessor | A central processing unit that is on a single computer chip. |
| personal computer (PC) | A small computer designed to be used by a single person at a time. |
| transistor | A small electronic device that can control the flow of electricity. |
| UNIVAC | The first computer to be sold to businesses. |
| vacuum tube | An electrical device with a switch that allowed current to flow through it or be turned off. They were large and often burned out. |
