Somewhere I read, If your eye is a window to your Soul, then your camera is surely a doorway to your heart?
WE CAN CLASSIFY CAMERAS IN MANY GROUPS:
COMPACTS, EVIL, DSLRS, MEDIUM FORMAT CAMERA, EXOTICS, ETC.
COMPACT CAMERAS (POINT & SHOOT):

EVIL (Electronic Viewfinder, Interchangeable Lenses) cameras:
This is a concept that manages to merge the best of both worlds. Whether the sacrifice of the optical viewfinder in exchange for a smaller size is worthwhile will be an entirely personal choice.
DSLRs:
MEDIUM FORMAT CAMERA :
Medium format cameras use film much, much bigger than 35mm or digital, and thus give much higher quality. It’s also almost as easy to use as 35mm and digital, and in some ways easier. With quality better than 35 mm or digital and almost equal ease-of-use you’ll see why it has always been a popular format for many kinds of professional photography, especially portraiture. Medium format typical film size is 6*4.5 cm size
Finally, EXOTICS is everything else, including all film cameras:-
– LARGE FORMAT CAMERAS:
The wooden box with bellows and a black cloth to hide the photographer. Their resolution can even beat that of MF digital backs but the large negative size makes everything harder, from buying film to developing and scanning or printing it.
Large format film size is upto 8*10
– RANGEFINDERS:
These are another alternative to DSLRs, where the optical viewfinder does not pass through the lens. This permits a smart manual focus system based on split screens. The most famous of these cameras are the Leica M family, and the last iteration, the M9, is one of the best digital cameras money can buy. Photojournalists and street shooters love them, but their learning curve is steep.
Article by: Pankaj Singh