Education is commonly divided into formal stages including preschool, primary school, secondary school, college, university, or apprenticeship. Formal education takes place in a structured school environment with classrooms and certified teachers. Preschool educates children ages 3-7 before primary school, which provides the first 5-7 years of formal education. Secondary education occurs in teenage years. Tertiary or higher education follows completion of secondary school and includes undergraduate and postgraduate degrees as well as vocational training. Vocational education focuses on practical skills for specific trades, while special education caters to students with learning or physical disabilities.