The Rating\Credit System Explained
 The Reputation (also known as rep)
Reputation is now at the centre of the support system. Reputation basically states if the user can be trusted or not. If a user provided you with support or gave some advice that helped you out, you can always add some reputation to that person. Reputation should be used principally when the advice was directed at us. Reputation should as well be principally given in the threads that request support or help. (This is a huge hint for the people asking for help in the free hosting section...) However, if the user directly gave you some advice that was clearly, not only misleading but also, intended of doing harm or messing up your computer/website/etc. then you should envisage of giving negative reputation. Be careful, as that feature is pretty powerful, and abuse can easily degenerate and get you banned. Don't act as a kid when you receive negation rep, but try to get some constructive criticism on how to improve the quality of your posts.
Reputation is like the tip you leave for a waiter at your table. You give them more if they were good (i.e. positive rep), and you give none (i.e. negative rep) if they were bad.
Corey has written a post explaining the intricate details of the system, if you are interested.
You might have noticed that now, along with the quote button, there is a "Thanks" link, with a thumbs up image, at the bottom of each post (except yours). Thanking is somewhat similar to reputation, but is still different. You thank someone that gave good information about any subject, you thank someone that help you clarify your point. You may also thank someone that hasn't help you but gave good advice to someone else and helped solve that person's problem.
Thanking does not give points, it's more of a casual action. It's like a big pat on the shoulder.
 Post Helpfulness
POST HELPFULNESS HAS BEEN TEMPORARILY DISABLED.
This last feature is only found in the free hosting section. The two thumbs are located right between the blue thanks button and the yellow quote button. This feature is used to indicate if the advice given in a post was useful. This is mainly to tell other users if the advice given helped you and if they should try it as well.
Credits are the currency of the x10hosting forums. Credits are like regular money, meaning that you receive then for doing some things (posting in the forums) and you can donate them or exchange them for services. However, keep in mind that not all forums distribute credits per port at the sate rate! Some forums give more credits per post, while others less. The rate at which credits are given also varies with your user group. How you manage your credits is left up to you.