Research (Terror From The Deep)
Research is a decisive factor in the contest of Man versus Alien. X-COM forces start out badly outclassed by their alien foes, but as they master alien technology, the battle swings to the Humans' favor.
Through research, X-COM forces gain access to vastly improved weapons technology, armour, base facilities, interception and transport subs, and a variety of other useful technologies. Researching captive live aliens provides information about the aliens' methods and traits, and is ultimately the only path toward winning the game.