Why do some basketball players wear the band around their ankles or knees?

I notice that some basketball players wear a band around their knees or around the entire shin portion of the leg. I there a reason why or is it just for show?Why do some basketball players wear the band around their ankles or knees?
hide their scars from being on their knees??

Some of those players have to service their stars *cough* *cough* (Lebron's bitches)Why do some basketball players wear the band around their ankles or knees?
Well, it could be for sweat??? Nah probably for support, or sponsorship deals etc...Why do some basketball players wear the band around their ankles or knees?
support