Bots can either be good or bad. Some bots simply are programmed to get attention by posting a bunch of bad stuff (like the ones above) but they are usually flagged. The good bots are programmed by people on steemit to do things like search for good articles and well written posts and upvote (or "like) them. There is a bot that automatically checks for plagiarism in people's posts so make sure you don't copy and paste anything! I have a lot to learn about bots too but you don't have to worry about them because there are a lot of people on this website that are determined to get rid of all the bad bots and spammers :)