Here is a some info on compression and file formats.

Describe the following compressed data formats:
AVI, GIF, TIFF, JPEG, MPEG-1,2,4, RealAudio
What type of applications each one is good for?
Common file formats are needed to transfer audio, video, and images between distributed systems. Coding in a binary file format

AVI (Audio/Video Interleave) - In AVI, picture and sound elements are stored in alternate interleaved chunks.

GIF (Graphic Interchange Format) - GIF was developed by CompuServe in 1987, with later features including interlacing, conspiracy, or an animation. Interlaced GIF displays images in two passes of alternating lines instead of loading them one of the time. Transparent GIF lets the background show through selected parts of image.
GIF is losing popularity due to the JPEG format when it comes to photos. Guess images are limited to 256 colors, JPEG can contain up to 16 million colors, and they look almost as good as a photograph.

TIFF (Tagged Image File Format) - a format for high-resolution bitmap images.

JPEG (Joint Photographic Experts Group) - ISO standard for still image coding; lossy compression and low complexity. The graphic format used most often to compress still images of complex pictures and photographs.
Two graphics compression techniques: lossy and lossless. Lossless techniques throw away redundant bits of information without affecting the quality of the image. Lossy techniques crunch files down smaller, but they lose image quality of the process.

MPEG (Moving Picture Experts Groups) - MPEG is a generic means of compactly representing digital video and audio signals. It is one of the standards for the compression and coding of motion video for CDs in digital storage. MPEG converts analog video signals into compressed video files. Because MPEG uses sophisticated compression techniques, compared to other audio and video and coding formats MPEG files are much smaller.
MPEG is a standard for compressing sound and movie files into an attractive format for downloading, or even streaming, across the Internet.

The MPEG-1 standard streams video and sound data at 150 kilobytes per second--the same rate as a single speed CD-ROM drive--which it manages by taking key frames of video and filling only the areas that change between the frames. Unfortunately, MPEG-1 produces only adequate quality video, far below that of standard TV. The standard in which Video CD and MP3 are based.

MPEG-2 compression improves things dramatically. With MPEG-2, a properly compressed video can be shown at the laserdisc clarity with a CD quality stereo soundtrack. For that reason, modern video delivery mediums, such as digital satellite services and DVD, use MPEG-2. The MPEG-2 video standard is used to transmit data in Hughes Electronics direct-satellite broadcast system DirectTV in the USA. Also the standard in which Digital Television set-top boxes and DVD are based.

MPEG-4 - the next generation of standard video and audio compression techniques.

Macintosh QuickTime - developed by Apple Computer, QuickTime is a method for storing sound, graphics, and movie files.

RealAudio - RealAudio uses a compression/decompression algorithm to convert analog sound signals into digitized sound.

Windows Media - Microsoft's multimedia decoder.