CAF (Core Audio Format) is a free audio container format developed by Apple and works on macOS 10.4 or later. It can also be opened on macOS 10.3 using QuickTime 7. Apart from audio, CAF can also hold multiple metadata such as file name, album name, composer, and more. It comes with a filename extension of .caf.
Apple QuickTime Player Soundtrack Pro Logic Studio
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