What is Data Compression ?

Compression is the reduction in size of data in order to save space or transmission time. For data transmission, compression can be performed on just the data content or on the entire transmission unit (including header data) depending on a number of factors.

Content compression can be as simple as removing all extra space characters, inserting a single repeat character to indicate a string of repeated characters, and substituting smaller bit strings for frequently occurring characters. This kind of compression can reduce a text file to50% of its original size. Compression is performed by a program that uses a formula or algorithm to determine how to compress or decompress data.

ADVANTAGES OF DATA COMPRESSION:

• Less disk space (more data in reality) (*)
• Faster writing and reading (*)
• Faster file transfer
• Variable dynamic range
• Byte order independent

Simplest answer Data Compression is taking a lot of data and shrinking it. Now there many methods of compression out there and they are not all simple. For a decent algorithm for text look for Huffman Run length encoded (this can also be used for graphics with some modifications.)