WMV stands for Windows Media Video.
WMV, manufactured by Microsoft, is often a generic name of Microsoft's video encoding solutions and doesn't necessarily define the technology exactly what uses. In WMV7, Microsoft has utilized its flavour of MPEG4 video encoding technology. Use a .wmv file either to download and play files as well as to stream content.
Windows Media Video is utilized for both streaming and downloading content through the Internet. Microsoft's Windows Media Player, an application bundled with Windows XP os's, lets you playback and manage a selection of video and audio file types, including WMA and WMV.