A crib mattress is a specially designed mattress for infants and toddlers that fits snugly in a crib. These mattresses are typically made from materials like foam or innerspring coils, providing a firm surface that supports safe sleep for babies. The firmness helps reduce the risk of suffocation and promotes healthy development. When choosing a crib mattress, it's important to ensure it meets safety standards and fits the crib properly without gaps. Many crib mattresses are also waterproof or have removable covers for easy cleaning. Parents should consider options that are free from harmful chemicals to create a safe sleeping environment for their child.