MPAI-HMC is a Technical Specification an implementation of which enables a human, either in an audio-visual scene  or represented as a Digitised Human in a Virtual Space to communicate with a Machine or a human in an audio-visual scene of a different Context by sending a Communication Item. The Machine responds by either producing au audio-visual scene or a Communication Item.

audio-visual scene is a scene with audio and visual attributes in a real space.

Audio-Visual Scene is a Scene with Audio and Visual attributes in a Virtual Space.

Machine is an Implementation able to receive, process, and produce Data having a Format specified by MPAI-HMC.

Communication Item is an Implementation of the Portable Avatar Data Type.