"Comments" are threads that people commment on that are on the home page. This one, for example.
"Votes" are the # of votes readers have submitted on games. For example Reader Scores (RS) and Hype Scores (HS).
This gives our readers a way of posting their review score of a particular game and it averages all votes for a total sum. Same w/ Hype score, games that haven't been released, so we see how much hype it is generating. If you vote on the RS or HS, your vote count goes up accordingly.