VOB, short for DVD Video Object, is used for storing the MPEG-2 video/audio, subtitles, menu contents, etc together into a stream form. Many popular video players support the VOB format, like VLC Media Player.

RMVB is short for Real Media Variable Bitrate. It is a popular file format developed by RealNetworks and is fully compatible with RealPlayer. Generally speaking, RMVB is widely used for delivering Asian content such as TV episodes.

3D refers to someting that has height, width and depth, providing the stunning stereoscopic vision. So far, 3D technology is growing in a slow pace, resulting in the limited amount of 3D videos on the internet.

SWF is an open file format developed for multimedia, vector graphics and ActionScript. It allows web browsers to play animation without using Java. SWF file can be played by Adobe Flash Player or any systems with the Flash plug-in.