If you use a computer, then chances are extremely high that you have heard the terms bits and bytes before. The RAM (random access memory) in your computer system is measured in bytes. The size of your hard drive (also sometimes called the hard disk) is measured in bytes. The files that you use, from Word documents to mp3 songs to mp4 videos to video games to software, programs and other applications, are all measured in bytes. When you browse the local computer shop to check out the systems that they have available, many of the specs you will see provided to tell you
Bits and bytes are not difficult to understand in you think of them in a certain way. For example, you can think of bits in terms of single number digits. 1 is a single number digit, as is 5 or 9. We combine single number digits together to then express larger numbers and values. Following that logic, 1234 is a number that has 4 digits, and 75 is a number that has 2 digits. Our common mathematical system uses a base 10 number system, which is expressed when you note that the 4 in the above example occupies the “ones place,” the 3 occupies the “tens place,” the 2 occupies the “hundreds place” and the 1 is in the “thousands place.” Any numbering system can work off of a base system of anything, and computer systems operate using a base 2 numbering system. This system is called the binary number system, and computers use binary digits to express values – that is where we get the word “bit.” Bit is short for “Binary digIT.” In binary numbers, each bit holds a value in increasing powers of two, though 0 and 1 are the same value as they are in our own base 10 numbering system.
Bits rarely come alone in a computer. They are usually bundled together in collections of 8 bits. An 8 bit collection is called a “byte.” A byte can be used to hold an individual character in a text document on your computer. If you were to go and open up Notepad, and then type a 6 letter word and save it, you would find that the file size is 6 bytes – one byte per each character or letter in the word. But if you were to look at that text file like you were a computer instead of a human, you would also see that each byte contains a number rather than a letter. That number is the ASCII code that corresponds to that specific character. There are 127 specific ASCII codes that correspond to letters and characters.
Today's computers do not deal in single bits and single bytes. They deal in many thousands and millions of bits and bytes, which is where the prefixes come in. A megabyte is abbreviated to MB and is worth 2^20 or 1,048,576 bytes. A gigabyte is abbreviated to GB and is worth 1,073,741,824 bytes or 2^30. You may have seen a terabyte being advertised lately, as well, in local stores and online. Terabyte drives are enormous. Abbreviated to TB, a terabyte is worth 1,099,511,627,776 bytes or 2^40.
So that's basically it. A bit is a binary digit and can hold a value of zero or one, and a byte is a bundle of 8 bits. Your computer uses this binary language to execute absolutely everything you do while you are using your computer system!
