Flash Video (FLV) is a container file format used to deliver video over the Internet
Flash Video is a container file format used to deliver video over the Internet because it forms small file volume with fast loading speed. 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.