3G2 is an audio and video format developed by Third Generation Partnership Project for CDMA-based (Code Division Multiple Access) phones. Actually it is an updated version of the 3GP file extension. Both formats are based on the ISO base media file format that facilitates presentation and interchange of the media. The 3G2 format is flexible and requires little storage space that is why it is mostly used by cell phones for saving files. However 3G2 movies can be played on computers but in some cases additional applications may be needed.

RM is a proprietary video container created by RealNetworks Inc. – the pioneers in streaming media over the internet market. This format supports DRM and was widely used to stream video and audio data online in the early 2000s with more than 80% of online streaming was in the RealMedia format. RM is supported by iPhone, Android, Windows and Mac. This container is often used by online radio stations. Nowadays it is still necessary to install Real Player plugin to be able to play RM files on such streaming websites.