The kinds of karma
| Comes from | Who can see it | What checks it |
|---|
| Post karma | Votes on your posts | Anyone, on your profile | Some subreddit minimums |
| Comment karma | Votes on your comments | Anyone, on your profile | Some subreddit minimums |
| Community karma | Votes inside one subreddit | Not shown publicly | That subreddit's AutoModerator, if the mods set it up |
| Total karma | Roughly the sum of the above | Anyone | Reddit's limits on new accounts |
Reddit says karma is an approximate reflection of your votes, so one upvote is not always one point. And it tells you not to chase it: its help page asks you to be a good contributor and let karma follow.
What it means for a marketer
Karma is a gate, not a goal. Many rooms won't show your posts until the account has some, and they look at account age too, so a brand new account with a great launch post often goes nowhere. Earn comment karma first, in small rooms about things you know. A few upvoted answers in your own field do more for a marketing account than a big total from memes, because mods read the history as well as the number.
I wrote the slow, safe version step by step in how to get karma on Reddit, and the difference between that and farming in karma farming vs warming up.