Rapid Share/Reactor

Can someone please explain these two to me and the connection between them.

What I Know: Or at least think I know

RS: With a monthly payment you can get access to links that are sort of like torrents that you DL using a Prog. like Flashget.
(Can Utorrent be used)

RR: Don't really know what this is, but Ive heard it being compared to RS. I couldn't find my Ratio.So what there is no ratio like Torrenting.
Are they links that come from RS, and do I use Flashget also.

Please Help
Thanx in Advance