Primary school and secondary school are two stages of formal education. Primary education is the first stage of formal education, which comes after pre-school or kindergarten education. It focuses on learning and educational activities that are designed to improve skills like reading, writing, and mathematics at the early stages of education. Primary education takes place in primary schools and elementary schools. Primary education often takes place in a single classroom with one primary teacher, fostering a stable and consistent learning environment.

Secondary education is the next step in education for children from 11 to 16 and are typically much larger schools compared to primary schools. Secondary education focuses on subjects like literary-philosophical studies, economics, social sciences, mathematics, physical sciences, earth sciences, and biological sciences. Secondary education prepares students for higher education and universities. The final two years of secondary education are often called Higher Secondary (HS), Senior Secondary, or simply the "+2" stage.

The age group of students in primary education is generally between 5 to 11 years, while secondary education deals with adolescents aged 12 to 18. Primary education prepares students for secondary education, while secondary education prepares the students for higher universities.

In some countries, primary education consists of grades one through five, while lower secondary education covers grades six through eight and secondary education covers grades nine through twelve. In other countries, primary education may last for six years, and secondary education may last for four to six years.