Microsoft Surface is a multi-touch product (developed by Microsoft) that incorporates both software and hardware technology that allow users to manipulate digital content by use of gesture recognition (human gestures are used as input as each human gesture is employed some functionality). This could involve some physical object or motion of hands(as a human gesture).It has a 360-degree interface, a 30-inch reflective surface with a XGA DLP projector underneath the surface and five cameras in the machine's housing record reflections of infrared light from human fingertips and objects on the surface. The surface can respond to 52 touches at a time.
The four main features of Microsoft Surface are: direct interaction (refers to the user's ability to simply reach out and touch the interface of an application in order to interact with it, without the need for any physical devices such as a mouse or keyboard), multi-touch contact (refers to the ability to have multiple contact points, unlike with a mouse, where there is only one cursor for interaction), a multi-user experience (more than one users can interact with it on different sides of the surface), and object recognition (refers to the device's ability to recognize the presence and orientation of tagged objects placed on top of it).
http://technisky.blogspot.com/2010/07/interface-that-can-respond-to-52.html