Lemon is a small, yellow citrus fruit that belongs to the Rutaceae family. It is known for its sour taste, which comes from its high citric acid content. Lemons are widely used in culinary applications to add flavor to both sweet and savory dishes. They are a rich source of vitamin C, providing health benefits for the immune system. Lemon juice is commonly used in beverages, dressings, sauces, and desserts.