WAV (or WAVE) is actually the first full-fledged audio format with good sound quality. It was developed quite a few years ago by the joint efforts of Microsoft and IBM. Sometimes this format is even called “Audio for Windows,” because it is the standard for storing audio stream for a traditional Windows desktop computer. Full name - Wave Audio File Format. The short name is derived from the English word wave ("wave"). The peculiarity of this format of digitized audio stream is the lack of compression. WAV files take up too much space, but it is ideal for storing high quality files in their original form.
FLV is a video file format developed by Adobe Systems. The name is an abbreviation of the full name Flash Video File. FLV format video files are Flash-compatible and usually contain various metadata (titles, audio, video, etc.). FLV-files are widely spread on the global network, in this format they make streaming video for YouTube, MySpace and other video hosting sites. Compared with similar formats, video files have a higher compression ratio. FLV files are easily converted to more common video formats.