While your usual digital camera probably has a single lens (that is the Single Lens of « SLR »), Stanford researchers are developping a camera with 12,615 more lenses. They are used to help build an image that is able to sense the depth of the subject. That way, you get the image, but also the distance and can build a 3D model of the subject. This is a 3D camera.
They say that because of the large number of lenses, the quality of the individual lens may not be a problem anymore. Thus, the cost of cameras may go down at the same time.
The current prototype is targetting 3 mega-pixels, but they expect to be able to build giga-pixel cameras this way.