There are many things that caulking can do. Filling gaps in siding and windows to help keep rain out. You can also caulk around bathroom fixtures and tubs to keep the water where it belongs. Caulking seams and cracks in your house is a great way to cut down on heat/cooling costs and save money! A caulking gun is the best way to apply caulk, allowing an even flow, with maneuverability to do what you want, where you want.