warship class capable of independent combat, patrol, and merchant escort operations

A corvette is a small, manageable and lightly armed war ship. During the Age of the Sail, corvettes were smaller than frigates and larger than sloops-of-war, they had normally a single gun deck. Almost all the modern navies use ships smaller than frigates for coastal duty, but not all of them use the term corvette (from the French corvair) or equivalent.

Corvette Dupleix (1856-1887).