FLV is a Flash Video container used on popular hosting sites that stores audio, video and other data. It often uses h.264 or h.263 codecs for video storage and MP3 for audio. There are a lot of programs for both Windows and Mac operating systems that are able to open .flv files.

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.