rm RealNetworks, an internet streaming Media Company, is credited as the developers and owners of the proprietary RealMedia multimedia container format. The filename extension .rm refers to this format which is used as an audio and video wrapper to distribute digital media content over the internet. The first version of this container was released in 1997 and has been popularized for its ability to unpack the digital stream while it is being downloaded over computer networks such as the internet. The format is platform agnostic and works equally well on Microsoft Windows as it does on Linux or Mac OS.
dv .DV is a file extension that provides for digital video cameras. This file extension is utilized by home and professional camcorders alike. It is the standard file format that prevails over other alternative video file formats. No other file format can stand up to the quality and utility of the .DV file extension and its other related file extensions, .DVCAM and .DVCPRO.