Flash video media container file
Flash was originally developed by Macromedia and is now owned by Adobe. Programs that open F4V files include Adobe's Flash Player and Windows Media Player. Apple's iOS, the mobile operating system used on the iPhone and iPad, doesn't include native support for the Flash plug-in but browser apps are available to enable Flash on the devices.
The general Flash file extension is SWF (Shockwave Flash). Other Flash video file formats include the FLV, F4P, F4A and F4B file extensions
Learn more about Flash and F4V files:
> Adobe provides more information about the Flash player on its website.
> Wikipedia has an entry about Adobe Flash.