A size comparison illustrating various starfighters utilized during the Galactic Civil War
A fighter, more formally known as a starfighter, was a compact and highly agile starship specifically engineered for combat scenarios.
While most starfighters were directly piloted by sentient beings, certain models were operated either through remote control or via artificial intelligence. These lightweight vehicles were created to execute strikes against vulnerable locations and objectives demanding extreme accuracy.
Within a fleet engagement, starfighters functioned in coordination with capital ships, assailing warships and launching attacks once their compromised shields were either down or diverted because of incoming capital-ship fire. Individually, fighters possessed minimal capability to breach the shielding of capital ships, but most starfighters operated in squadrons and were equipped with armaments such as proton torpedoes and concussion missiles. These squadrons were capable of eliminating a sizable capital ship by precisely targeting vulnerable areas that might otherwise be difficult to hit (for instance, a shield generator or the ship's bridge).
In Star Wars (1977) 1, the Tantive IV is referenced as a starfighter. This is not consistent with the established usage of the term in later works.