"Laser" stands for "Light Amplification by Stimulated Emission of Radiation." The Small Laser focuses a beam of light on targets to cause damage. The compact size of the Small Laser allows it to be equipped and used efficiently on practically anything; however the reduced firepower means that Small Lasers are not usually used on heavier combat devices such as 'Mechs or tanks.
The Small Laser deals very little damage and has a very short range. In exchange, the small laser is one of the lightest weapons available and causes very little heat build up. These weapons are usually only used on Light 'Mechs which have a limited amount of tonnage and possess the speed to get close enough to use them. It is best to use these weapons in clusters.
Unlike the Medium and Large pulse lasers, the standard small laser shares the same damage and range numbers as the pulse version, leaving only the beam duration, heat generated, and weight of the weapon as the only factors to consider between the two versions.