An LED lamp (or LED light bulb) is a solid-state lamp that uses light-emitting diodes (LEDs) as the source of light.

Benefits include:

• Long service life
• High energy efficiency
• Reduced carbon footprint
• Contains no Mercury
• Lifetime is unaffected by cycling on and off
• Mechanically robust
• Turns on instantly
• Compact
• No glass tubes to break (Some models have a decorative glass bulb)
• Resistant to vibration and impact due to internal parts being rigidly supported
• LED lamps can be made dimmable over a wide range
• No minimum current needed to sustain lamp operation
• LED lights have also become very popular in gardening and agriculture. First used by NASA to grow plants in space, LEDs came into use for home and commercial applications for indoor horticulture (aka grow lights). The wavelengths of light emitted from LED lamps have been specifically tailored to supply light in the spectral range needed for chlorophyll absorption in plants, promoting growth while reducing wastage of energy by emitting minimal light at wavelengths that plants do not require. The red and blue wavelengths of the visible light spectrum are used for photosynthesis, so these are the colors almost always used in LED grow light panels.

INTERESTING FACT
In 2009 the exceptionally large Christmas tree standing in front of the Turku Cathedral in Finland was hung with 710 LED bulbs, each using 2 watts. It has been calculated that these LED lamps will pay for themselves in three and a half years, even though the lights run for only 48 days per year.