A coffee grinder is a device used to crush and grind coffee beans into smaller particles, which enhances the flavor and aroma of brewed coffee. There are two main types of grinders: blade grinders and burr grinders. Blade grinders use a rotating blade to chop the beans, while burr grinders crush the beans between two surfaces, providing a more consistent grind size. Using a coffee grinder allows coffee enthusiasts to enjoy fresher coffee, as whole beans retain their flavor longer than pre-ground coffee. The grind size can be adjusted depending on the brewing method, such as French press, espresso, or drip coffee, ensuring optimal extraction and taste.