Light-Emitting-Diodes are like small bulbs which range from size of 2mm to 8mm across. LEDs do not contain a filament to emit light, instead as the name suggests, they contain a diode which emits light when current flows in the reverse bias of LED. Light is emitted when electrons vibrate at a specific frequency. When electrons are vibrated within a range of even more specific frequency, specific wave length of electromagnetic radiation is emitted which results in specific colors of light. There are mainly four different LEDs out of which three LEDs emit monochromatic light of Red, Green and Blue colors. These three colors are primary colors and any other color can be created by mixing different intensities of any two primary colors. The fourth led emits white light which is created by mixing all three primary colors.
LED as a single unit emits a significant amount of light bit it is not enough to light up a room or an area therefore many LEDs are placed on a reflective panel and when lit together, collectively LEDs emit adequate amount of light.
Light sources which use LEDs as fundamental unit to emit light are now preferred over Incandescent light bulbs and florescent tube lights because the later two are filament based device. LED being filament-less device can withstand more electric shocks and physical shocks which increases their life span and the ability to use them in devices that undergo rough and tough conditions such as in car lights and traffic signals.
LED lights are more energy efficient as they consume much lesser power and emit the same intensity of light as incandescent and florescent lights therefore they are good for your pocket.
Florescent lights contain vapors of heavy metal mercury and poisonous phosphates which can prove to be harmful for the environment and disrupt the ecosystem of an area where as LEDs do not contain any such harmful material.
An LED can provide light for about 50,000 hours therefore an LED light source does not need constant replacement.
Initial cost of an LED light source is usually high and many people may not be able to afford it. LEDs also need a much lesser voltage of 12V to function therefore on may have to pay to change the power supplies of all the light sockets.
Many LEDs can be placed on reflective panel to emit light beam. These panels can vary in shapes and sizes to fit your need. Different colors of LEDs can also be used to add a decorative touch to the ambiance you are trying to create. LED Lights are mostly monochromatic but one can also find the devices which use different colors which flash at different intervals of time.
Many LED based products are famous such as LED Modules and LED Tubes which are used as a light source, LED Bars and LED Flex are used as decorative devices.
LED suppliers also supply LEDs to factories which manufacture different electronics. LEDs are used in home appliances as signaling devices such as those little lights in your dishwasher, washing machine, toasters and etcetera.