A coffee filter is a thin, porous material used to separate coffee grounds from brewed coffee. Typically made from paper, cloth, or metal, it allows liquid to pass through while trapping solid particles. Coffee filters come in various shapes and sizes to fit different types of coffee makers, such as drip coffee machines and pour-over systems. Using a coffee filter is essential for making a clean cup of coffee, as it prevents sediment from entering the final brew. The filter also plays a role in the flavor, as it can affect the extraction of oils and compounds from the coffee grounds, influencing the overall taste of the beverage.