Data compression is an important tool that minimizes the size of digital data. Without it, many features of Internet would not be practical, or even possible. This site discusses "the principles and practice of data compression," and examines common techniques for different types of information. The author considers some algorithms and coding methods, such as Huffman coding and the Blahut algorithm. JPEG, one of the most popular image compression formats, is demonstrated as well. A few programs, source code examples, and papers are available for download. Pop-up windows and advertisements are an annoyance on this site, but they are not overly noticeable.