blackhat techniques refer to aggressive tactics used in SEO to rank sites, which pushes the boundaries of search engine guidelines and can get sites banned
White hat is the opposite of Black hat. White hat means 'ethical,' originally in the eyes of Google, but now more so in the eyes of the search community as a whole. Though MSN has this love hate relationship with clever black hats. Google white hat and read up on it. White hat is the way to go if you're playing chess. Black hat is short term checkers - hit the mall money. UNLESS... (anyone? ...