A computer is an information processing machine.
Computers come in various forms. A personal computer may be a desktop, a laptop, a tablet, a phone, or a watch. There are also servers housed in racks in data centres, quantum computers in research establishments and tiny devices embedded in kitchen appliances and cars.
A computer can process information in a myriad of ways. It can store it for retrieval later. It can reformat it to make it easier to understand. It can filter out unnecessary detail. In fact, as the British mathematician, Alan Turing, proved in the 1930s, it can perform any operation that can be written down precisely.
When you use a computer, you feed information in, you tell the computer to process it in some way, and it produces some sort of result.
You can feed in all sorts of information.
- You can type in text with a keyboard.
- You can create a photo with a camera.
- You can record sounds with a microphone.
- And you can get all sorts of information from a memory stick or the Internet.
But a computer won’t do anything until you tell it what you want it to do. The instructions you give it are called a program. Some programs are supplied with the computer and some of those will start when you turn on the machine. Others you start yourself by clicking an icon or typing a command into the command window. These are the apps.