Grade school is another name for elementary school, the first stage of formal education where children typically learn from around ages 5 to 11. In grade school, students progress through different grades (kindergarten through fifth or sixth grade, depending on the school system), learning fundamental skills like reading, writing, arithmetic, science, and social studies.

The term comes from the way schools organize students by grade levels, with each grade representing roughly one year of learning. First graders learn basic addition and subtraction, while fifth graders tackle multiplication, division, and fractions. Each grade builds on what came before, like climbing steps where you need to master one level before moving to the next.

Grade school is where most people learn to read their first chapter books, make their first presentations, conduct their first science experiments, and navigate friendships outside their family. It's called the foundation of education because everything you learn later, whether in middle school, high school, or beyond, depends on the skills you first develop during these grade school years.

Some people use grade school and elementary school interchangeably, though elementary school is more common today. You might hear adults say, “I've known him since grade school,” to mean they've been friends since they were very young.