What are the red lines behind the goalie net in hockey?

The zones on a official hockey rink are the defending zone (where players try to defend and protect their goal or net), the neutral zone (where is the center zone and players try to get the puck in the their opponent's defending zone which is also their attacking zone and where players get the puck out of their defending zone) and the attacking zone (where players try to get the puck in their opponent's goal or net).