Curtains serve several purposes such as providing privacy, reducing light and drafts, and decorating windows. There are many types of curtains defined by their pleating styles like pinch pleat, box pleat, and goblet pleat curtains. Curtains are necessary for privacy, cost effectiveness as they can fit any sized window, and come in various fabrics and colors. Proper selection, hanging, and care of curtains ensures they last and serve their functions well.