Rep (Reputation) points, before the sleek new changes made to Deeperblue, were known as karma, or karma points. Reputation points (positive or none) are given by moderators, mentors and members to other moderators, mentors, and members alike, depending upon what you thought of this or that person's threads and posts. Clicking on little weight scale at the top, right corner of each post frame is how you initiate the Reputation window.
Well isn't this nice...I'm going to give you a rep point as I teach you how to spread the love...or in some cases discerning unapproval.
I click on the little weight scale icon, it opens a new, smaller Reputation window (picture included below). I either leave the "I approve" bullet highlited, or not...but in this case I definitely approve of your plea for answers.
So then I'll type you one of my trademark not-so-clever-messages, then I click "Add to Reputation" and I get a warm, fuzzy feeling inside...but I think it's from all this vodka I'm drinking.
Use it kindly and wisely. Although I should know better, I give it out for the silliest reasons sometimes. I use'em for saying hello to members that I haven't heard from in a while, or as little treats for when somebody has reached a new personal best. Or just because I like somebody.
This only works for a bit, as you can't really give someone a lot of reps in a row. A friendly reminder will tell you to spread it around for a while, then try it again. You can check your reputation points and their respective messages in your User Control Panel, or User CP.
hope I helped.