WHAT IS FLV? Flash Video (FLV) is the name of a file format used to deliver video over the Internet using Adobe Flash Player. The most recent public release of Flash Player supports H.264 video and HE-AAC audio. Flash Video content may also be embedded within SWF files. Notable websites of the Flash Video format include YouTube, Google Video, Yahoo! Video, Reuters.com, hulu.com, etc. SWF (acronym of “Shockwave Flashâ€) actually is a Flash movie, and it can be viewed as a Flash animation format, while the FLV is Flash Video, which is a Flash video format. Both of them can be created by Adobe Flash.