How does a computer work?

Like all digital machines, a computer changes writing, images, and sound into a special numerical language. It is a binary (or two-part) language that has just two numbers: 0 and 1. These numbers are called “binary digits,” or bits for short. In a digital machine, the numbers take the form of electric signals. With a 1 the electricity is switched on and with a 0 it is switched off. Information of all kinds, then, is turned into electrical on-off signals arranged in countless individual patterns. These patterns can be stored, sent along digital pathways, or converted back into forms that we can use and understand with extraordinary speed and accuracy. Bits enter a personal computer from the keypad, mouse, microphone, and scanner. They are received and sent out by cable or broadband modem technology, as well as stored in various memory devices. The computer screen, printer, and speakers convert the bits into forms of information that we can use.