Proton torpedoes were a type of ordnance used throughout the galaxy. Its most notable use was during the Battle of Yavin, when Luke Skywalker destroyed the first Death Star by launching a pair of proton torpedoes into a thermal exhaust port. There were also upgraded versions that sometimes possessed target locking abilities, as well as upgraded versions of the target locking variants themselves.
Proton torpedoes came in a wide array of sizes and yields; from massively powerful capital ship weapons designed for orbital bombardment, to small but nimble fighter-grade weapons like those Luke Skywalker employed against the first Death Star. A number of torpedo designs were shielded to protect them from being shot down either by skilled pilots or the target's defensive flak guns.
Small starfighters like the Rebel Alliance X-wing and Y-wing fighters often had their laser weaponry complemented by ordnance launchers capable of firing proton torpedoes. The energized torpedoes carried a devastatingly powerful blast, and could be fired at much greater ranges than the standard laser cannon. The torpedoes were exceptionally maneuverable, able to make a 90 degree turn within a turning circle of a meter, enabling them to be used against starfighters, such as when Corran Horn in his X-wing used them against Erisi Dlarit's TIE Interceptor. 
- ↑ The nucleus of the hydrogen atom, of positive charge. 
- ↑ Unit of radiation in the quantum theory of light, in which light is required to have particle character.