Everything Inside a Computer
A computer can hold an astonishing variety of things: documents, photos, music, videos, games, and more. It can store more information than a huge library. This raises a basic but fascinating question. All of these different kinds of content, words, pictures, sounds, are so different from one another. How can a single machine store them all? The answer is surprisingly simple and elegant.
The Language of Ones and Zeros
At the deepest level, a computer stores everything using just two symbols: one and zero. Each single one or zero is called a bit, short for binary digit. The word binary means based on two. A bit can only ever be in one of two states, like a tiny switch that is either on or off. A computer's storage is made of an enormous number of these tiny on-or-off elements. That is the entire alphabet a computer uses: just on and off.
Turning Everything Into Bits
If a computer only understands ones and zeros, how can it store a photo or a song? The trick is that all information gets converted into binary code, long strings of bits. A letter of text is assigned a particular pattern of bits. A picture is broken into tiny dots, and the color of each dot is written as bits. Sound is measured many times a second, and each measurement is recorded as bits. So everything, whatever it is, becomes one long sequence of ones and zeros.
Why Bits Work So Well
Using only two states might seem limiting, but it is actually a great strength. Two states are easy and reliable for a machine to represent, for example as a switch being on or off, since there is little room for confusion between just two options. And while one bit holds very little, bits can be combined. With enough bits side by side, you can represent any number, and from numbers, anything else. Billions of simple bits together let a computer store a whole world of information.
Source
This article was written using information from Wikipedia.