This can be a consequence of a car that only gets minimal use. Especially if you are habitually quite light on the brakes.
Brake parts can seize up due to rust, other corrosion, brake dust, road salt , road dirt etc. . Rotor discs can get rusty, even overnight, Brake calipers normally have parts that slide freely allowing the brakes to retract themselves when released.These may be be clogged and jammed. Regular use helps keep parts moving.
It could be the handbrake which can jamb on . These will sometimes release themselves if you reverse the car. There may be a sudden clunk as it releases. But its not a permanent cure.
You can tell whether its front or back by which wheels get especially hot. All brakes will get hot anyway,enough to burn you , but a siezed one will be extra hot..
It needs attention. If you are lucky a brake service and thorough cleaning of parts may be enough. Some brake parts may need replacing, and there is always the possibility of another problem such as faulty hydraulics.
Its possible that giving the front discs and calipers a thorough washing with a hose ,and a fairly soft brush might clean them up enough for a temporary fix to get you to the garage. Dont use a pressure washer or stiff brush (unless you really know what you are doing) as these can damage rubber parts.
On a car that gets little use its a good idea to deliberately apply the brakes quite hard every now and then (when safe of course) to help keep parts moving.
