While surfing the Internet, you will undoubtedly find text, graphics, audio and video files to download. Multimedia files in particular can be very large, which means they can move very slowly across the global network. Downloading these files could take hours. To make efficient use of space and speed things up, most large files are compressed.
File compression reduces the size of a file and the time it takes to download.
Compression software uses complex mathematical equations to scan a file for repeating patterns in the data. It replaces the data with smaller codes that take up less room. For example, one way compression software works is to replace repeating text characters with a code that also notes the locations of those characters in the data. With a picture, it would find all of the red pieces, for example, and replace them with a code. To view compressed files, you need a compatible decompression program that can read these codes and convert the data back to its original form.