When you look at LED lights you will often come across the term 'lumens' - lumens measure how much light you get from the light bulb. In the past we have always based our light buying purchases on watts and how many watts the bulb is; however, watts are a representation of the how much energy the bulb consumes. Lumens is a new way of looking at how much light you will get in exchange for your money - think about when you buy a steak you can see the price per kg, or wine price per litre. So lumens allow you to think in the same way. You can make a purchasing decision based on lumens and the more lumens, the more light. If you want a dimmer light then go for less lumens, a brighter light then more lumens.
This is a typical comparison between watts and lumens: