HPS + MH bulbs (lamps) - HPS bulbs - CMH bulbs - CFL bulbs (lamps)
HPS (High Pressure Sodium) bulbs are suitable for plants in the vegetative and flowering phase. HPS Lights emit white light.
CMH (ceramic metal halide - also LEC or CMD) bulbs are suitable for plants in the vegetative and flowering phase. CMH lamps produce the most sun-like spectrum of light.
CFL bulbs are energy saving bulbs and are suitable for plants in the vegetative and flowering phase. They are more suitable for smaller spaces.