Icing is when the puck crosses the goal line in an attacking zone when it was passed from the defending zone without anyone touching it.
Ice involves a center red line and two blue lines, one on each side of the red line.
If the puck is passed over two lines it is offside. Also, if a player is in front of the puck, when it is carried across the attacking blue line, then it is offside too. Inline is by definition, a non-contact game. Depending what division, Ice is a contact game. In Australia, Junior C and Senior C are non-contact, Junior A,B and Senior A,B are contact.