Windows Media Video (WMV) is a file type which can contain video in one of several video compression formats developed by Microsoft. The original video compression format used in the file, also known as WMV, was originally designed for Internet streaming applications, as a competitor to Real Video. The other compression formats, such as WMV Screen and WMV Image, cater for specialized content. Through standardization from the Society of Motion Picture and Television Engineers (SMPTE), WMV9 has gained adoption for physical-delivery formats such as HD DVD and Blu-ray Disc. Though sometimes used interchangeably, note the distinction between Windows Media, the file type, and Windows Media Video, the video compression format. Windows Media the file type is a container (in the Advanced Systems Format) which can contain video in one of several different video compression format, only one of which is the Windows Media Video video compression format, alongside audio in an audio coding format.
Audio Video Interleaved (also Audio Video Interleave), known by its initials AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows software. AVI files can contain both audio and video data in a file container that allows synchronous audio-with-video playback. Like the DVD video format, AVI files support multiple streaming audio and video, although these features are seldom used. Most AVI files also use the file format extensions developed by the Matrix OpenDML group in February 1996. These files are supported by Microsoft, and are unofficially called "AVI 2.0".