RMVB is a file format with a variable bitrate developed by RealNetworks. Actually it is an improved version of RM format. It gives greater bandwidth to videos that are difficult to compress. The extension keeps a high video definition. RMVB files are very popular in Asia and they are not supported by all popular players, so the easiest way to playback them is to convert them to another most common format.

WMV is a codec usually used for video compression in ASF format. It is possible to open WMV files both on Mac and Windows with almost any player or convert the format to another one. WMV supports DRM protection that prevent users from copying information. It is the main reason why the format is widely used by companies that sell digital video and audio online. Also the format is well-known among users because WMV files are used on popular Xbox 360 devices. Low bitrate makes such files an ideal solution for HD DVD and Blu-ray discs.