Bits and bytes: Do you get it yet?

It's hard to wrap your mind around it, but digits don't have to be the numbers 0 (zero) through 9 (nine). The ten digits we have our minds wrapped around are decimal numbers, decimal meaning ten. Why do we use decimal numbers? Only because we have ten fingers (another name for finger is digit).

Since computers don't have fingers, but lights and switches (mostly teeny tiny switches called transistors), they count in a manner that is convenient for them. A switch (transistor) has only two "digits," 0 (zero) for off, and 1 (one) for on. Take a word that means "a system of two" (binary) and add it to the word "digit," and you get:

binary + digit = bit

A bit can only equal zero or one. A binary digit, or bit, is just a number, a digit with two possible values. So, if we count with bits instead of decimal digits, we count the same way, but skip all those other numbers (2 through 9). 

In the decimal number system, we count like this: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12... 

In the binary number system, we count the same way, but skip anything that has the numbers 2-9 in it, like this: 0, 1, 10, 11, 100, 101, 110, 111, 1000.

Stop and think about it. Count to ten in binary.

Now let's talk about bytes. If you take eight bits (any combination of 1's and 0's) and string them together, we call it a byte. A byte is a string of 8 bits. A byte isn't a digit, but we use it like one because bits all alone don't tell us much. If you take eight bits (a byte), however, you can create 256 possible unique combinations of 1's and 0's. Long ago, a "code" was established for what these combinations could represent. That code uses the first bit for the computer to check for errors, and the other seven bits to represent letters, numbers and symbols like the dollar sign and such. The code is known as ASCII, which stands for the American Standard Code for Information Interchange.