Corvettes were a type of starship that were part of the United Federation of Planets Starfleet inventory.
Like the perimeter action ships, corvettes were patrol combatants (Ships of the Star Fleet) designed for high-warp military engagements. Unlike those ships, corvettes were designed for longer-duration missions, had slightly larger crew sizes and had a higher deadweight tonnage (though less than that of destroyers).
Examples of this type include the Mugato-class that first saw action during the Kelvan War in 2285. (Orion Press: In Harm's Way)
Klingons also fielded corvettes, like the K'pak-class. (Star Trek: The Stoneship Files: "A Knight without Armor")
During the 25th century, the Orion Syndicate also built and fielded its own corvettes to serve as light raiders. While fast and highly maneuverable, they were generally not considered a threat to larger assault or exploration cruisers. (Star Trek Online: Valkyries)
Though officially termed a tactical escort, the Defiant-class was sometimes described as a corvette class. (The War of the Masters: "The Silence Ends")