The full form of FLV is Flash Video. It’s used on Computing ,File Extensions in Worldwide

Flash Video (FLV, F4V) is a container file format used to deliver video over the Internet using Adobe Flash Player versions 6-10. Flash Video content may also be embedded within SWF files. There are two different video file formats known as Flash Video: FLV and F4V. The audio and video data within FLV files are encoded in the same way as they are within SWF files. The latter F4V file format is based on the ISO base media file format and is supported starting with Flash Player 9 update 3. Both formats are supported in Adobe Flash Player and currently developed by Adobe Systems. FLV was originally developed by Macromedia.