A missile boat or missile cutter is a small, fast warship armed with anti-ship missiles. Being smaller than other warships such as destroyers and frigates, missile boats are popular with nations interested in forming a navy at lower cost. They are similar in concept to the torpedo boats of World War II; in fact, the first missile boats were modified torpedo boats with the torpedo tubes replaced by missile tubes.
An Osa I class missile boat in 1983. The Osa class are probably the most numerous class of missile boats to have been built.
HSwMS Ystad of the Swedish Navy 2017.
A Gepard-class vessel of the German Navy
An anti-ship missile is a guided missile that is designed for use against ships and large boats. Most anti-ship missiles are of the sea-skimming variety, and many use a combination of inertial guidance and active radar homing. A large number of other anti-ship missiles use infrared homing to follow the heat that is emitted by a ship; it is also possible for anti-ship missiles to be guided by radio command all the way.
RGM-84 Harpoon firing from USS Leahy in 1983
Martel guided anti-ship missile
The MBDA Exocet anti-ship missile under a Dassault Rafale
BrahMos, a supersonic cruise missile, compatible of being launched from multiple platforms.