Is a media container format designed for streaming over the Internet. Used on popular video hosting sites. Video is usually stored in h.263 and h.264 formats, audio is a in MP3 or other less popular codecs. FLV-file format is a bit stream, which provides high-quality image even at low bit rates.
AU is a file extension for a sound file format belonging to Sun, NeXT and DEC and used in UNIX. The AU file format is also known as the Sparc-audio or u-law fomat. AU files contain three parts: the audio data and text for a header (containing 24 bytes) and an annotation block.