A tricopter is similar to a model helicopter except that it has three vertical rotors as opposed to a helicopter's one.
It has a video camera mounted on it that transmits a live video stream to the person controlling it from the ground. The camera also records the video at HD resolution.
The problem with the "FPV Plane" was that it had to be flown in a large uninhabited area, meaning that a flight required much preparation. This is one of the reasons I started building the FPV Tricopter.
Although it looks complicated, the construction and the way it works are simpler than for a helicopter.
The video sent to the ground has a simple OSD(On Screen Display) with basic information about the battery, orientation, speed, etc.