Deciduous teeth, also known as baby teeth or primary teeth, are the first set of teeth that develop in children. They typically begin to emerge around six months of age and are usually complete by age three. There are 20 deciduous teeth in total, which include incisors, canines, and molars. These teeth play a crucial role in a child's development, aiding in chewing food and helping with speech. Deciduous teeth eventually fall out, making way for permanent teeth that will replace them. This transition usually starts around age six and continues until the early teenage years.