Beams of energy, particles or radiation used offensively.
Laser weapons are not as widely used as blasters since they have a higher energy demand although some race learn to overcome the energy demands
These are beams of light, high temperature streams of energy that melt through a target. Most are invisible to the human eye, but the more powerful one have a photothermal effect.
These are simple particle beams, not just Lasers (beams of light) but particle beam which often heat up the target.
Depends on the designer and technology.