What are the benefits of licenced theme

What's the different between free theme and licenced theme? What are the benefits of licenced theme?

The only difference is the links in the footer. Paid version is links free version. This improves your page ranking in comparison to free version of a theme. but if you are not very concerned about .. Free versions are also very cool

Okay. Can i use the licence on the other websites or just one website?

You can use it unlimited times for different domains.

Thanks