A bright yellow citrus fruit originating from Asia used for culinary and medicinal uses. Lemons are available in many varieties including Meyer lemon which is less tart and is actually a hybrid and the Eureka Lemon is the tart lemon typically found in grocery stores.
Lemons are so widely in cooking the many uses are too numerous to list but typical uses are for beverages, dressings, desserts, and in general to increase acidity levels in a dish to balance flavors.