All Terrain Armored Transports, or AT-AT's for short. They first appear in the Empire Strikes Back. AT-AT's are 50 feet tall and have the appearance of a giant four-legged monsters. The head serves as the control center and a mount for the walker's weapons.
Designed to strike awe and terror into Rebels hearts, the Imperial Star Destroyer and the rest of the Empires fleet of space vessels maintain order in the galaxy through shows of power and ruthless fighting tactics. Is a capital ship. It first appears in the first seconds of Star Wars and is the signature vessel of the imperial fleet.
TIE Fighters are one-man starfighters with a spherical cockpit, hexagonal wings and two chin-mounted laser canons. The basic TIE fighter first appeared in A New Hope and is the primary Imperial fighter seen in the Original Trilogy.