RAM, Real Media Audio Metadata File (.ram)
The RAM Audio file format
RAM is a music/audio file that gives the user the liberty to play audio format both offline and online on his or her device of choice by streaming. This link file is used by RealPlayer to perform the above function while storing the original audio format in other RealMedia files such as RM files which are stored in the URLs of the RAM files.
Technical details of RAM files
Audio data connected to a RAM file can be played while it is being downloaded. Furthermore, this audio data is sent with the use of RAM extension's own proprietary transport protocol called RDT. This information was initially not disclosed to anyone and has been made public only recently by via the Helix Community Project.