It is a very thin ribbon you hold between fingers of each hand and insert between adjoining teeth and scrape along the teeth sides, especially close to gums. The ribbon, or floss, helps loosen debris by gently moving it up and down and back and forth between the teeth. Flossing is a proven method for loosening debris from hard-to-reach surfaces of your teeth and gum lines. Next to brushing, flossing is a highly effective method for removing plaque on tooth surfaces your brush can’t reach very well. It can also come in different flavors.