Voting power means the strength of an account to upvote other users posts. Breeze has inflation based voting system where every next upvote requires more power than previous and this renew on daily basis.
To generate voting power, a user needs to have TMAC tokens in his account. It keeps increasing at a rate of 30 VP/TMAC/hour. Maximum VP a user can have is 16000. Once it is fully or partially used, new vp starts generating again.