Even today, people continue to say "light bulb" when they mean lamp – and "lamp" when they mean luminaire. To put the record straight: the lamp is the light source. No lamp, no light.

There are energy-efficient, long-life lamps available today for every lighting assignment. They are distinguished by

• the way they generate light
• their lighting characteristics
• their power consumption in watts
• their geometric design.
  
  

Edison's incandescent lamp is the prototype of all electric light sources but it has two major drawbacks: it produces more heat than light and, at a maximum of 1,000 operating hours, it has only a short service life. There have long been lamps around which operate for longer and with much greater energy efficiency.

First choose the lamp, then the luminaire

Lamps are major contributors to lighting quality. They produce the light – which is why they should be selected first, before the luminaires. Which lamps are suitable depends on the lighting application and the requirements the lighting needs to meet. What is the lamp's purpose – to provide economical lighting over long operating periods or decorative lighting for a relaxing atmosphere?

The energy efficiency of the lamps used is an increasingly important consideration. Criteria for it include

• luminous efficacy
• life
• lamp type.