RealMedia is a proprietary multimedia container format created by RealNetworks with the filename extension .rm. RealMedia is used in conjunction with RealVideo and RealAudio, while also being used for streaming content over the Internet. Typically these streams are in CBR (constant bitrate), but a container for VBR (variable bitrate) streams named RMVB (RealMedia variable bitrate) has been developed.

A RealMedia file consists of a series of chunks that can be of several different types: