Fast attack craft versus corvettes

What is the difference between a fast attack craft and a corvette?

Corvettes generally have substantially greater endurance and can remain away from port for a week or longer.

The distinction offered is how long a vessel is expected to remain away from port. A fast attack craft normally operates for a short period, perhaps a day or two at most. A corvette is expected to remain at sea for about a week or longer. The exact expectation depends on the navy using the designation.