Reputation points are given at a whim by one member to another. You can get positive, neutral, or negative reputation.
Positive reputation is often given as a reward for a useful contribution. CD values correct and valuable information over sheer volume and low-value information.
Neutral reputation is often given in place of positive, when you have done something not quite right but the giver does not want to punish; also when the user simply wants to communicate with you but not impact your reputation.
Negative reputation is given when you break the unwritten and social-norm rules on CD. One standard is the Grandmother test: If you wouldn’t say it to Grandma (assuming you like and respect her), don’t here either. Incorrect information is worse than no information, so presenting incorrect information (unless labeled as speculation) is frowned upon. Attacking someone is frowned upon, so be gentle always, and scold in private. Wasting time/energy/resources of others is also best not done. As with trolling, baiting, etc. We’re a civil bunch here, integrate and you’ll be fine, buck and fight and you won’t.
It probably says something that it’s harder to elaborate on negative than positive. Some people in our world have a harder time picking up social cues than others; this is how they are wired, and we try to forgive. But some people are intentionally evil, and those shouldn’t participate here.
Also, you will be corrected from time to time, as were we all. Take these to heart and learn from them, it will serve you well on CD and in life. People who offer criticism are putting themselves out for your benefit: Just thank them and learn.