Imperial Star Destroyers are a large class of spaceships mostly manufactured by the Astrotech Cartel for the New Shi'ar Imperium. They are used mainly by the Imperial Guard. They have hulls about 1000 feet long, making them comparable in size to Basestars and Asteroid ships as well as the largest Bulk cruisers.
An Imperial Star Destroyer cannot land on planets, so it relies on Airspeeders designed for transporting cargo and passengers. It carries a squadron of Starfighters or TIE fighters. The Star Destroyer of course is equipped with Hyperdrive for interstellar mobility. When moving within a local solar system, a Star Destroyer will use three large nuclear-rocket engines.
A Star Destroyer generally is armed with on-ship weapons.