Is a the most popular media container format on phones without the support of 3G, which is currently somewhat outdated. Its main advantage is a compactness. Video data here gets stored in h.263 or MPEG-4 formats. AAAC-LC or AMR-NB are available for audio.
Is a binary stream media container format that combines several codecs of texts, subtitles, audio and video data. It can be used on web pages for video playback. It has a lot to do with the OGG format. Exists support for popular codecs MPEG-4 and MP3.