The Media Transfer Protocol (MTP) is a protocol that allows media files to be transferred atomically to and from portable devices.

The Media Transfer Protocol (MTP) is an extension to the Picture Transfer Protocol (PTP) communications protocol that allows media files to be transferred atomically to and from portable devices.

Whereas PTP was designed for downloading photographs from digital cameras, Media Transfer Protocol allows the transfer of music files on digital audio players and media files on portable media players, as well as personal information on personal digital assistants.

The USB Implementers Forum device working group standardised MTP as a full-fledged Universal Serial Bus (USB) device class in May 2008.

See wiki page.