Can anyone please explain to me in simple words, the difference between frigate, destroyer and cruiser?
Frigate is a name which has been used for several distinct types of warships at different times. It has referred to a variety of ship roles and sizes. From the 18th century, it referred to a ship smaller and faster than a ship-of-the-line, used for patrolling and escort work rather than fighting fleet actions. In modern military terminology, the definition of a frigate is a warship intended to protect other warships and merchant marine ships and as anti-submarine warfare (ASW) combatants for amphibious expeditionary forces, underway replenishment groups, and merchant convoys.
A corvette is a small, maneuverable, lightly armed warship, smaller than a frigate but larger than a coastal patrol craft.
In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet or battle group and defend them against smaller, short-range attackers (originally torpedo boats, later submarines and aircraft).
A cruiser (From Dutch Kruiser, "something that crosses") is a classification of large warship. Historically they were generally considered the smallest ships capable of independent operations — destroyers usually requiring outside support such as tenders — but in modern parlance this difference has disappeared. In modern warfare the cruiser has virtually disappeared, supplanted in all roles by the destroyer.
In naval terminology, a destroyer is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet or battle group and defend them against smaller, short-range attackers (originally torpedo boats, later submarines and aircraft).