MP4 (MPEG-4 Part 14) is a video container format based on QuickTime MOV. But unlike MOV, it adds support for other MPEG features. MP4 supports video (MPEG-4 Part 2 and MPEG-4 Part 10/H.264), audio (MP3, AAC, SLS, TTSI, and ALAC), and subtitles (MPEG-4 timed text). It’s this codec combination that gives MP4 its flexibility.
Windows Media Player VLC Media Player, Apple QuickTime Player 5KPLayer
M4V is a digital video container format developed by Apple Inc. It is pretty similar to the popular MP4 in terms of structure, but M4V files can sometimes be DRM protected. Today, M4V is the primary video format for iTunes Store videos and can multiplex together multiple audio and video data.
Media Player Classic VLC Media Player KMPlayer Zoom Player