nursery school
A school where very young children go to play and learn.
A nursery school is a place where very young children, usually ages 2 to 4, go to learn and play before they're old enough for kindergarten. Think of it as school for toddlers and preschoolers: they spend a few hours singing songs, playing with blocks, painting pictures, and learning to share toys with other kids.
The word “nursery” originally meant a room where babies and young children are cared for, so a nursery school is like extending that caring environment into an educational setting. Teachers at nursery schools help little kids develop basic skills like holding a crayon, listening to stories, and taking turns. They're learning how to be students, even if they don't realize it yet.
Some people call it preschool, which means basically the same thing. The main difference is subtle: nursery school sometimes refers to programs for slightly younger children (2- and 3-year-olds), while preschool often means the year right before kindergarten. But many people use the terms interchangeably, and the exact meaning can vary by region or country.