How Does Compression Work

Overview

Many people don't understand compression -- how do you make something smaller? In some ways you don't -- you just encode the data in a more efficient way. This article will explain a few basic types and concepts about data storage and compression. These concepts are far simpler than people realize -- it's just the implementation details can be a pain.
Basically, compression on computers is achieved by looking for commonality (in shape or pattern), and then saving the description of that shape or pattern (using tables or mathematical algorithms) instead of saving the whole image itself. If you don't get it, read on, and it may become more clear.