A phaser is a fictional energy weapon commonly featured in science fiction, particularly in the Star Trek franchise. It is designed to emit a beam of energy that can be set to various levels, allowing it to stun or kill targets. The versatility of phasers makes them popular among characters in the series, as they can be adjusted for different situations. Phasers are often depicted as handheld devices, resembling a pistol or rifle, and are used by members of the United Federation of Planets. They are powered by energy cells and can be recharged, making them a practical choice for space exploration and combat scenarios.