The Oculus Rift is a Virtual 3D gaming system in which is a HMD (Head Mounted Display). You can plug it in and sync it with your web cam and then play any game that is compatible with Oculus Rift, such as Minecraft or Half Life 2 (Lots of other games available and or in the process). And is compatible with: Windows, Linux and OS X meaning that if you have an Apple Mac or HP you cannot use Oculus Rift.
The Oculus Rift is a 7 inch (the prototype was 5.6 inch) retangluler screen that you put over your eyes and the picture of the game comes up on the screen, the left eye sees extra area to the left and the right eye sees extra area to the right. This copies normal human vision, which does not 100% overlap either, although the overlap area is smaller on the Rift than in real life. It ways approximately weighs 379g (the prototype wieghed 90 grams left and was increased due to the increase of the screen size).
The resolution is 1280×800 (16:10 aspect ratio), which leads to an effective of 640×800 per eye (4:5 aspect ratio). However, since the Rift doesn’t feature a 100% overlap between the eyes, the combined horizontal resolution is effectively greater than 640. The image for each eye is shown in the panel as a pincushion type image that is then corrected by the headset, generating a spherical-mapped image for each eye. The panel’s resolution is expected to be upgraded to at least 1920×1080 for the final consumer version.
Here is a video using the Oculus Rift and explaining it a little more:
