According to Stanford Children's Health, the newborn skull consists of five bones: two frontal bones, two parietal bones and one occipital bone. These bones are held together by fibrous material known as "sutures."
The sutures in a baby's skull allow the bones to move as needed during birth. They also expand to allow for the growth of the skull bones and help growth to occur evenly, as Stanford Children's Health explains. The sutures meet at two main points in the skull, known as fontanelles. The fontanelle typically called the "soft spot" occurs at the junction of the frontal and parietal bones and usually closes by the age of two. The posterior fontanelle, which typically closes within the first months of a baby's life, occurs between the parietal bones and the occipital bone.