Used cooking oil is the oil that remains after cooking food, often from frying or sautéing. It can come from various sources, including vegetable oils, animal fats, and olive oil. Once used, this oil can contain food particles, flavors, and other impurities, making it unsuitable for further cooking. Instead of discarding used cooking oil, it can be recycled or repurposed. Many facilities collect it to convert into biodiesel, a renewable energy source. Additionally, used cooking oil can be transformed into soaps or bio-lubricants, contributing to sustainable practices and reducing waste in landfills.