A diaper cover is a protective outer layer worn over a cloth diaper. It helps to contain moisture and prevent leaks, keeping the baby's clothing dry. Diaper covers are typically made from materials like PUL (polyurethane laminate) or wool, which are both waterproof and breathable. These covers come in various styles, including snap, hook-and-loop, and pull-on designs. They can be used with different types of cloth diapers, such as prefolds or fitted diapers. Diaper covers are reusable and can be washed, making them an eco-friendly choice for parents looking to reduce waste.