Curds are solid pieces formed when milk coagulates, separating from the liquid whey. This process typically occurs when an acid, like lemon juice or vinegar, is added to warm milk, or when rennet, an enzyme, is used. Curds are a key ingredient in many dairy products, including cheese and yogurt. The texture and flavor of curds can vary depending on the type of milk used and the method of coagulation. They can be soft or firm and are often used in cooking, baking, and as a topping. Cheese is one of the most popular products made from curds.