A convertible (commonly known as a 'cabriolet' in Europe) is an automobile that can 'convert' from an enclosed top vehicle into an open top vehicle by means of a roof that can be removed or retracted or folded away.
The roofing material is most often a flexible fabric such as canvas or vinyl, and most convertibles have a mechanism driven by electric motors that retract or raise the roof cover.
In some vehicles, known as 'hardtop convertibles' the roof can be a series of folding steel panels. When in place, the hard roof makes such vehicles look more like conventional fixed roof vehicles. In other vehicles, only a smaller section of the roof area is 'convertible'.
Traditionally, the term 'roadster' was applied to a vehicle with no permanent roof covering or side windows, but today that name is most often used to describe any 'convertible sportscar'.