A coupé — also known as coupe — is a car with a fixed-roof body style usually with two doors.

The term coupé was first applied to horse-drawn carriages for two passengers without rear-facing seats. The early coupé automobile's passenger compartment followed in general conception of the design of horse-drawn coupés. The French variant for this word thus denoted a car with a small passenger compartment.

Hemmings Classic Car describes a coupé as "any two-door other than a two-door sedan, smaller than a related four-door in the same model line" and that "all two-door two-seaters with a solid roof are coupes."

Automobile manufacturers have begun to use the term loosely and include sporty variants of their sedan lineup that feature sloping rooflines.

More Info: en.wikipedia.org