Lower the power consumed, more efficient the product is. We are living in an age where energy efficiency is given a consideration because of two reasons; one being that humans have noticed the outcome of their careless waste of energy as wasted energy always ends up in the form of heat energy and increases the average temperature of our environment, now resulting in global warming. It's the selfish human act why ice-caps are melting, water level of the oceans is rising and we are running to make every specie of animal into an extinct memory to be placed and viewed in museums only. Another reason why energy efficient products are preferred is because they knock off a significant amount of cash from electricity bill back into our pockets.
Our nights are more productive, all thanks to bulbs. We all use incandescent bulbs or florescent light bulbs. These two filament based light sources are very famous but starting from recent past, they are being replaced by LED based light sources. LED is short for Light-Emitting-Diodes. LDEs are like small bulbs but they don't not contain filament, instead light is emitted out of the diode resulting as an energy release when electrons vibrate at specific frequency. LED as a unit has a size of 2mm to 8mm across, therefore light produced by a single unit is not enough. Many LEDs are placed on a panel to emit light adequate to light up a room.
LEDs being such a small unit require very less power to emit required light hence they are considered to be one of the most energy efficient light sources compared to incandescent light bulbs and florescent tube lights. An LED can provide light for 50,000 hours therefore LED lights do not need to be frequently replaced.
LED Power supplies are even lower than 110V therefore one has to buy a special device for them but many times an LED Module or LED Tube come fitted with it. LEDs require 12V of electricity only. Therefore an LED power supply is necessary otherwise the device can malfunction.
You can find different types of LED Power supplies. There are those powerful enough to handle the LED devices of the whole house. There are also those which com with a dimmer so you can increase and decrease the intensity of light emitted by your LEDs. Some manufacturers also provide the LED power supplies with remote controls so they can be turned on and off without moving from your spot.