All boats heel to some extent. Heeling occurs when the wind fills the sail, creating pressure that pushes the sail down and the boat up. The boat will heel to whichever side the vessel sails are. Some boats, such as keelboats, have huge ballasts that allow extensive heeling. Healing may be scary to new cruisers and sailors, but if you do it correctly and your boat is designed to heel, there is no reason to worry about it.