Definition: Stance is the way in which a surfer stands on his/her board. There are two "stances." A surfer can stand as a "regular foot" with his/her left foot leading and right foot on the rear or tail of the board. On the contrary, if a surfer stands the opposite way, that is with the right foot forward and left foot on the tail, this is termed "goofy foot." Rivalries between goofies and regulars are common, but there is really no advantage to either.
A truly gifted surfer can switch his stance from goofy to regular depending on the wave.