Warships utilize a number of very powerful electron beam cannons that can fire across exceptionally large distances and still maintain a high level of accuracy. These cannons are typically recessed into the hull of the ship, with a movable focusing lens near the end of the barrel that allows the beam to be fired at different angles. (A typical electron beam cannon can be fired, for example, at a 30 degree angle).
Due to powerful electromagnetic-interference (as a result of both ECM and natural stellar phenomenae) it is very hard to "lock on" to an enemy ship with computer targetting. Because of this, most warships are equipped with a large number of these cannons, firing all of them simultaneously in the general direction of an enemy ship, hoping to score a hit.