Traveling a Roadway for a Bit to Get a Byte

Traveling a Roadway for a Bit to Get a Byte

Two humans communicate when one person says something and the other person listens. If you ponder that a little more, the two people need to understand the same language. To communicate, the person speaking has to say a bunch of words. The words themselves are sounds that are combined. From one perspective, two people communicate by speaking the same language, but at the other end of the spectrum, you could think of those same people communicating by making a bunch of sounds.

Similarly, computers can communicate with each other using a network, but there are many perspectives. For instance, I'm using Microsoft Word to write the text in this book. When I send the file to my editor at Cisco Press, she uses the same program to open the file and edit the chapter. So, you can think of our computers as speaking the same language. In this case, both of our computers understand files formatted for use with Microsoft Word, which is a word processing program.

It is relatively easy to think of a file that contains the text for this chapter. However, at the same time, the file is really just a bunch of bytes, with each byte containing 8 bits. It's a little like when you put a file folder in a real file cabinet, you might be thinking that you're doing simply thatstoring one file in a cabinet. From a different perspective, if the folder contains a bunch of pieces of paper, you are also storing those pieces of paper. Similarly, when a computer stores a file on a disk drive, it is indeed storing one file. However, from a different perspective, the computer is also storing the bits that make up the file.

Computer files consist of a bunch of binary digits. Humans normally use decimal numberingyou know, 0, 1, 2, 3… 9, with 10 unique digits. Binary uses only two digits: 0 and 1. That's because computer hardware, at the most basic low level, can store one of two electrical states in its memory, and those represent a binary 0 or 1. And because the phrase binary digits takes five whole syllables when speaking (in English, at least), and it's used so often, someone shortened the term to simply bits.

To speak to another person, you use a language, but your voice actually makes a lot of small individual sounds. It's the combined sounds that make up words and sentences in your chosen language. Similarly, a computer might have a Word document or any other file that's useful to a computer, but the contents of these files are just a bunch of small individual pieces of information, called bits. It's the combined bits that make up the parts of the file that the computer has in memory. (By the way, the term byte refers to a set of 8 bits on most computers.)