x10points are the currency you trade here with other members by doing them a favor or w/e and you can "buy" things that will affect your forum name, thread name, make a thread a sticky, and other stuff like that. Meanwhile, x10Cash buys you things like a domain, unsuspension, paypal payouts and things like that and you cannot trade it with other members. However you can "convert" x10points to x10cash as a 20:1 ratio, also you normally would receive x10cash by completing surveys listed
here