With the development of video and audio, many video and audio formats are becoming common used. Previously there are only avi and mpeg kinds of formats and now, there are more than 20 kinds of video and audio file formats.

FLV is one of the new and developing video file, for the development of flash and online video site such as YouTube. People want to upload DVD videos to YouTube first need to convert DVD videos to FLV or they convert avi to flv and so on. Of course if people download videos from YouTube, it must be .flv too. So they need to convert flv to mp4 or convert flv to avi for use with a video converter thing.

FLV is not just a video file formats, it is a flash video used to deliver video over the Internet using Adobe Flash Player, and it content may also be embedded within SWF files. They mostly used for web or online service.

Today more and more video formats are becoming popular because of the technology of communication and video frequency. We need to change, change our mind to follow them.