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.

MXF is a media container developed by SMPTE association for professional use. MXF implements subset of Advanced Authoring Format (AAF) data model and nowadays become a standard in professional non-linear video editing. MXF files can be compressed with almost any codec and easily converted to any popular video format. Worth noting that Sony's, Panasonic's and Canon's implementation of this format carries a lot of incompatibilities, that was a big flaw of this container. These issues were addressed in the 2009 version of the standard.