Par or Par Can A fill or spot type of light. The can holds the bulb. The style of light depends upon the lamp installed, either flood or spot.
Fresnel (Firnel) A fixture with a lens. Some Fresnel are adjustable from flood to spot. The light even when set to spot and a defuse (soft) edge. Can use both gels and barn doors with this light.
Ellipsoidal (Lico) A spot light with both a lens and well defined beam edge. This type of light comes with in many variations. Some have a fixed beam, others have interchangeable lens in order to adjust the size of the beam. These lights can use barn doors, gel and Gobos.
Follow Spot A manned light with features similar to ellipsoidal's but controllable by the operator. This type of light normally has multiple gel, a shutter to close the light, an iris to shrink the size of the beam. These lights normally have a focus to sharpen or defuse the edges of the light beam.
Intelligent Light A general category for lights that have multiple functions and are controlled (or programmed) remotely.