I was talking to insomniasexx about this. To summarize what I learned:

The big hub wheel in the top left is the website logo. It's a static image link that brings you back to your feed. Similar to the "reddit" logo in the top left of reddit.

The little one to the right of your name is kind of like your current karma. I'm not quite sure on the specifics on how to fill it up, but it has to do with people sharing your comments/links. Similar to reddit.

Unlike reddit, once it fills up, you get a badge to give out. This is kind of like reddit gold, but doesn't do anything. It's like how reddit gold says "this is an excellent post". Same goes for badges.

For the hubwheels next to the submissions and comments: The ones next to submissions means you share the submission. Anyone following you will see it on their feed if you share it. Think of your account as a subreddit, and people can subscribe to you. Anything you share is kind of like reposting it into that subreddit.

The hubwheels next to comments are different. Essentially they are just an upvote. They say "this is a great comment." As far as I'm aware, clicking on it does not share it with your followers. It just acts like a regular upvote.

Hopefully that answered your question. Also, if I got anything wrong (hopefully not), insomniasexx should be here to correct me.