Transmedia = device agnostic media
It used to be that every medium was tied to a specific device. Television was something you watched on TV; radio was something you listened to on the radio; a movie was something you went to the movies to see. No longer. Transmedia is what happens when media become uncoupled from the devices that were invented to deliver them. It's an organic and inevitable response to the world we live in. Like, how else would you tell a story?