First, the origin of destroyers.
A century ago, the British engineer Walter Sr invented an underwater ship, which can dive quickly under the water. After it was filled with explosives, it took a very domineering name, called torpedo. Later, old Walter sold the intellectual property of this thing to the British navy, but the British navy thought it was of little use, so old Bai sold the property of the torpedo to France. At that time, the ships fighting at sea were relatively large. The French regarded them as treasures and produced many speedboats with torpedoes, which were specially used by British warships. At that time, the British were very angry and immediately invented a ship that moved very fast. Adding guns to the ship can catch up with and destroy torpedoes and torpedo boats, and adding torpedoes to the ship itself can also attack the opposite big ship. The invented ship is the first destroyer in the world. The first destroyer was launched in 1893 and named Hawok.
Second, the role of destroyers.
First of all, the role of destroyers is anti-torpedo, but with the birth of missiles, destroyers are no longer needed to chase torpedoes, but destroyers are not retired, but more and more, mainly because there is something more terrible than torpedoes underwater: submarines.
During the First World War, submarines came into people's sight. German submarines once destroyed most allied merchant ships and cruisers at sea, and hydrophones and sonar reaction devices were brought to warships. Because of its high speed, destroyers first play an anti-submarine role, detect submarines through sonar systems, and then drop a large number of deep-water bombs, which has become the main function of destroyers at present.
Of course, destroyers also have the functions of rescuing, launching torpedo attacks and acting as frigates, but expelling submarines is still the main task of destroyers.