The Imperial Navy had the most awesome array of ships and weapons in the galaxy until the fall of the Empire. The command ship was the Imperial Star Destroyer, a capital ship designed especially for the Empire. The ship has 60 turbolaser batteries, 60 ion cannon batteries, holds 3 squadrons of tie fighers, 2 of tie interceptors, 1 of tie bombers, several lambda class shuttles, an array of scout and attack walkers, bulding materials, transports, probe droids, tractor beam projectors, and more. To hold all this, it must be a large ship right? Well, its over one and a half kilometers in length! If you think that's big, consider the lenght of the super star desroyer, which is a craft used as a flagship. They are over four times the length of a regular Imperial class star destroyer!
Death Star II can be seen in the background of this picture. The Death Star was a huge battle station with a giant laser cannon that had the power to destroy an entire world with one shot. One blast from the death star laser was about the same as the combined firepower of every ship in the imperial fleet if they were all combined into one shot. The amount of power needed for such a blast was so immense that the largest power source in the galaxy had to be built. This huge power source was the Death Star's weakness, as the rebels exploited the explosive core twice to destroy both death stars.
On the other end of the scale is the tie fighter. This small fighter is equipped with two laser cannons and that's about it. It has no deflector shiels (since the Empire is more concerned with saving money than the lives of its pilots), no hyperspace capabilty, and cannot carry any warheads unless it is modified. It has two solar panels on the side for emergency power. The small size and lack of deflector shields and warheads make tie fighters extremely fast. They are so difficult to hit in a dogfight, that their lack of deflector shields is almost made up for. If a tie takes a good hit, it's done for, but if it gets behind you, watch out!
Umm, here's a lambda class shuttle. They are used for transport.