RealMedia (RM) was an older proprietary multimedia container format developed by RealNetworks. It was primarily used for streaming audio and video over the internet, utilizing codecs like RealVideo and RealAudio for efficient compression and playback.

RealMedia was created by RealNetworks in 1997. It was primarily designed for streaming media over the internet. RealMedia files typically contain RealAudio and RealVideo streams, which are highly compressed to facilitate efficient streaming, even on lower bandwidth connections. The format saw significant use in the late 1990s and early 2000s, particularly with RealPlayer, one of the earliest media players supporting streaming over the internet. Despite its early popularity, advancements in technology and the rise of more versatile formats led to a decline in its usage.