In naval
A navy is the branch of a nation's armed forces principally designated for naval and amphibious warfare; namely, lake- or ocean-borne combat operations and related functions...

 terminology, a destroyer is a fast and maneuverable yet long-endurance warship
A warship is a ship that is built and primarily intended for combat. Warships are usually built in a completely different way from merchant ships. As well as being armed, warships are designed to withstand damage and are usually faster and more maneuvrable than merchant ships...

 intended to escort larger vessels in a fleet
Naval fleet
A fleet, or naval fleet, is a large formation of warships, and the largest formation in any navy. A fleet at sea is the direct equivalent of an army on land....

, convoy
A convoy is a group of vehicles, typically motor vehicles or ships, traveling together for mutual support and protection. Often, a convoy is organized with armed defensive support, though it may also be used in a non-military sense, for example when driving through remote areas.-Age of Sail:Naval...

 or battle group
Carrier battle group
A carrier battle group consists of an aircraft carrier and its escorts, together composing the group. The first naval task forces built around carriers appeared just prior to and during World War II. The Imperial Japanese Navy was the first to assemble a large number of carriers into a single...

 and defend them against smaller, powerful, short-range attackers. Destroyers, originally called torpedo-boat destroyers in 1892, evolved from the response of navies to the threat posed by the torpedo boat
Torpedo boat
A torpedo boat is a relatively small and fast naval vessel designed to carry torpedoes into battle. The first designs rammed enemy ships with explosive spar torpedoes, and later designs launched self-propelled Whitehead torpedoes. They were created to counter battleships and other large, slow and...

. Growing from earlier defensive developments, the torpedo boat destroyer (TBD) first appeared as a distinct class of warship when HMS Havock
HMS Havock (1893)
HMS Havock was a Havock-class torpedo boat destroyer of the British Royal Navy built by the Yarrow shipyard. She was one of the very first destroyers ordered by the Royal Navy. She had a 240 tons displacement, a speed of 27 knots, and was armed with a single 12-pounder gun, three 6-pounders, and...

 and Hornet
HMS Hornet (1893)
HMS Hornet was a Havock-class torpedo boat destroyer of the British Royal Navy.Built by Yarrow & Company, London, she was laid down in July 1892, launched on 23 December 1893 and completed in July 1894. She served all her service life in Home waters. She served for fifteen years before being sold...

 were commissioned into the Royal Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

 in 1894.