An FLV file is a flash-compatible video file exported by the Flash Video Exporter plug-in (included with Adobe Flash) or other program with FLV file support. It consists of a short header, interleaved audio, video, and metadata packets. The file stores audio and video data in a similar format used by standard Flash (.SWF) files.
The FLV format is an open format that is also supported by non-Adobe/Macromedia programs. FLV files may be exported from QuickTime Pro or other applications that can export to the QuickTime file format.
Macromedia was acquired by Adobe in 2005, so Macromedia Flash Player is now Adobe Flash Player.