An assault frigate is a specialized version of the smallest warship. Above that are destroyers, cruisers, and battleships. And there are capital ships (dreadnaughts, carriers, motherships) that are even larger.
The largest railgun on a battleship can launch slugs weighing about a ton at near-relativistic speeds, hitting targets at ranges exceeding 100 km. You can have 7 of them on one ship, if you have the right model.
Other ship types use lasers and/or missiles. Each one has its advantages and disadvantages.
Speed (and transversal) is life. ;)
I am looking for EVE battle videos on Youtube... heh