How do the Marina Micro LED lights work?

I am looking for a good little night light for my fish, I was thinking about getting the Marina Micro LED light set. But I am a little confused. When I go into the store I see something called the "Hub" you have to purchase and then I see the lights. So does this mean that it requires you to purchase two separate things? Or when you purchase the hub do you get 1 light that comes with it? Also, about how long would you say that LED lights have a life of?