Bits, bytes and why you should care
Before we start talking about how information is sent from computer to computer via the internet, it helps to understand what bits and bytes are. Computers communicate by sending bits (individual units of data) to each other using electricity, light or radio waves.
What is a bit?
Computers operate on the premise that an electrical current running through the circuit system can exist in two states, either being present when the switch is ‘on’ or absent, when it is ‘off’. Each of these two states is assigned a value — the ‘off’ state is 0 and the ‘on’ state is 1.
In the same way that we count using a base-10 or decimal number system, where digits can take any value from 0 to 9, computers use a base-2 or binary number system, where the binary digits can take a value of either 0 or 1. Each bit (short for Binary digIT) is a single 0 or 1, corresponding to a single switch in the circuit. Using multiple bits, more numbers can be represented.
So what is a byte?
Most of the time, in computers, bits are bundled together in 8-bit collections, called bytes. Using 8 bits in a row, 256 different values (ranging from 0 to 255) can be expressed. One thousand (technically, it’s 1024) bytes together is about a kilobyte and 1024 kilobytes together is a megabyte.
But what about human language?
When we type into a computer, we’re using the ASCII character set, which includes letters, numbers, spaces, punctuation marks, carriage returns and line feeds. There are 127 different ASCII characters, and each is represented by a different byte. If you typed the word ‘one’ into a text document and saved it, the whole file would be 3 bytes in size. If you typed ‘one two’, the file would be 7 bytes in size because of the space in between the two words. In this way, all of the characters we type in are converted into bits and bytes by computers.
Using electric pulses, light beams or radio waves, computers send bits (and bytes) to each other to communicate all this information.
For a more detailed explanation of bits, bytes and counting using the binary system, see this how stuff works article.