MPEG stands for Moving Picture Expert Group in charge of the development of standards for coded representation of digital audio and video. There are several audio/video formats which bear this group's name, such as MPEG1, MPEG2, MPEG4. View MPEG to DVD Burner and AVI to MPEG Converter.
MPEG1 format is often used in digital cameras and camcorders to capture small, easily transferable motion video clips. It is also the compression format used to create Video CDs. In addition, The well-known MP3 audio format is part of the MPEG1 codec. View DVD to MPEG1 Ripper.
MPEG2 format, a video standard developed by MPEG group, is often used in digital TVs, DVD movies and in SVCDs. It is not a successor for MPEG1, but an addition instead. both of these formats have their own purposes in life. MPEG1 is meant for medium-bandwidth usage and MPEG2 is meant for high-bandwidth/broadband usage. View DVD to SVCD Ripper.
MPEG4, the latest compression method standardized by MPEG group, is used for both streaming and downloadable web content, and is also the video format employed by a growing number of portable video recorders. One of the best-known MPEG4 encoders is DivX which since version 5 has been fully standard-compliant MPEG4 encoder. View DVD to MPEG4 Ripper.
MPEG7 doesn't itself offer any new encoding features and it is not meant for representing audio/video content, unlike its siblings MPEG1, MPEG2 and MPEG4. Instead, it offers metadata information for audio and video files, allowing searching and indexing of audio/video data based on the information about the content instead of searching the actual content bitstream.
MPEG7 is based on XML and therefor is universal and all the existing tools that support XML parsing should be able to read the data as well, provided that they can ignore binary parts of the file.
MPEG7 is not used at the moment, but it is under serious development and standardization process at the moment and hopefully we see first fully featured MPEG-7 tools within few years.