A four-year-old is a child who is typically in the preschool stage of development, usually between the ages of three and five. At this age, children are becoming more independent and are often eager to explore their surroundings. They are developing language skills rapidly, learning to form sentences, and can express their thoughts and feelings more clearly. Socially, four-year-olds enjoy playing with peers and are beginning to understand the concept of sharing and taking turns. They often engage in imaginative play, using toys like action figures or dolls to create stories. This age is crucial for emotional and cognitive development, laying the foundation for future learning.