A file extension is the part of a computer file name that comes after the dot. File extensions are generally a three or four letter acronym that describes either the file type or the application that handles it. Shockwave-Flash was developed by Macromedia to handle animation and video content. It was part of Macromedia's suite of programs designed to support the development of web pages. Format-FLV files are formatted according to the SWF formatting language. The file contains a header describing the encoding of the contents of the body of the file.Playback-F lash video is popular for video players embedded in web sites. YouTube videos are stored in FLV files. Future-Macromed ia merged with Adobe Systems, and so Flash is now known as Adobe Flash.