A Missile was a powerful projectile weapon that was shot out of launchers that were either attached to vehicles or hand-held launchers. They had a large range of fire, while some could be directed towards a certain target. They also had a big detonation range. Missiles were normally used to take down vehicles, or large enemy target.
Missiles could be one of several kinetic weapons. There are proton torpedoes - which are used by bombers and cruisers to punch through shields of enemy capital ships, concussion missiles - which are typically used as a cheaper alternative to torpedoes or as antifighter weapons, and diamond boron missiles - which don't punch through shileds, though they really don't need to.
Most missiles are capable of penetrating enemy shields without exploding, though there are exceptions. Diamond boron missiles, which are high powered, long range missiles, typically do not, though their radius and damage easily make up for that. Proton Torpedoes are often too slow to hit small, fast vessels such as fighters and some corvettes; concussion missiles can, though they do inferior damage. In many cases, the right missile must be chosen for the right job, such as anti fighter duty falling usually on concussion missiles.