MTP mode means that a device uses media transfer protocol, a method of communication that is designed to allow easy transfer of audio and video files between mobile devices. MTP is a common feature found on mobile phones, MP3 players and digital cameras.
MTP is a central part of the Windows media platform and is compatible with Windows operating systems. Devices using MTP typically have a USB connection that allows users to connect the device directly to a computer for easy transfer. Devices that use a non-Windows operating system typically use mass storage class mode, or MSC, as opposed to MTP.