There are essentially three types of modern cameras: DSLRs, mirrorless bodies, and rangefinders. There are a few other formats that mostly fell by the wayside, however, as time marched on, such as the zone focus camera and the TLR. This neat video takes a look at using a TLR, including its unique experience and images.
Coming to you from Steve O'Nions, this video follows him as he uses a TLR camera on a landscape shoot. TLR stands for "twin-lens reflex" and refers to the fact that the camera actually has two lenses: one for creating the image and one for composing it. Both lenses are the same focal length and their focus mechanisms are locked together, though the focusing lens is normally of a lower quality simply since it is not used for actually exposing the image. The image from the focusing lens is reflected via a mirror (thus the "reflex") to a focusing screen on top of the body, thus making the camera conducive to being used at waist-level. Perhaps even more interesting than that is that they mostly output 6x6 square images! I personally love the shooting style and have enjoyed my Rolleiflex TLR for years, and I would snap a digital version up in an instant, though given the added mechanical complexity, I doubt we'll ever see such a camera beyond mirrorless imitations. Check out the video above to see it in action.