Piracy can mean different things; it can be a crime that is committed. A human on a ship at sea is called a pirate and usually has small, fast boats. Pirates use such boats to attack other ships, which are usually large cargo ships.
For as long as ships have sailed the sea, there have been pirates.Piracy still happens often in the Gulf of Aden, mostly by Somali pirates. Ancient Egypt and the Romans, Medieval kings, and the British Empire dealt with pirates. Fighting pirates has sometimes been one of the most important roles of a navy.