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 and bedding 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 pull-on and snap closures, and can be adjusted for a snug fit. They are reusable and can be washed along with the cloth diapers, making them an eco-friendly choice for parents looking to reduce waste while caring for their babies.