A preschooler is a child between the ages of about three and five, too young for kindergarten but old enough to learn through play, basic lessons, and social interaction.

Preschoolers are in that energetic stage where they're learning new things constantly: how to share toys, how to follow simple rules, how to use scissors, and how to recognize letters and numbers. They ask endless questions (“Why is the sky blue?” “Where does rain come from?”) because their curiosity is exploding. A preschooler might struggle to tie their shoes or sit still for long periods, but they're developing the skills they'll need when they start kindergarten.

The term can also describe anything relating to this age group. A preschool classroom has small chairs and tables, colorful posters, and lots of hands-on activities. Preschool books use simple words and bright pictures. When someone says a TV show is appropriate for preschoolers, they mean it's designed for young children who are still learning basic concepts about the world.