Simply put, Gaze is the HoloLens equivalent of a mouse. Now, instead of moving your hand to move the cursor around, you move your head. HoloLens uses the wearer's head position and orientation to cast a ray. At the end of that ray is the cursor. When the user moves their head, the cursor moves accordingly. As the cursor moves over or touches holograms, you can combine Gaze with the other members of GGV to interact with objects.
Now, let's start setting up the manager object and the cursor we need to start the most basic interaction.