Below Higher Education the system can be seen as consisting of four levels:

Children 3 to 5 years old in Spain have the option of attending the Pre-school stage (infantil or popularly known as preescolar), which is non-compulsory and free for all students. It is regarded as an integral part of the education system with infants' classes at almost every primary school. There are some separate nursery schools (Colegios Infantiles).

Children (whose parents chose that they should) enter pre-school (Educación Infantil) in the autumn of the calendar year in which they turn three years old. Following this pattern, the ages given here as corresponding to the different phases are the ages turned by children in the calendar year in which the academic year begins. Age ranges are inclusive: 3 to 5 years of age is 3 academic years.

Spanish students aged 6 to 15 undergo primary (colegio) and secondary school (instituto) education, which are compulsory and (like the preceding preschool from age 3) free of charge. Successful students are awarded a Secondary Education Certificate, which is necessary to enter the post-compulsory stage of Schooling (principally the Bachillerato) for their University or Vocational (Formación Profesional) Studies. Once students have finished their Bachillerato, they can take their University Entrance Exam (Pruebas de Acceso a la Universidad, popularly called Selectividad) which differs greatly from region to region. The compulsory stage of secondary education is normally referred to by its initials: ESO (Educación Secundaria Obligatoria).

Structured as two cycles of three years each:

The second of these two cycles is included in the general state provision of education and, although not compulsory, is followed by nearly all children. The first 'cycle', nursery care, is largely privately provided and funded although there are some subsidies.

Structured as three 2 year cycles:

Compulsory Secondary Education (Educación Secundaria Obligatoria or ESO) is structured as two cycles of two academic years each (total 4 years):

Upon finishing ESO the student has a number of options, including:

Spanish Bachillerato is the post-16 stage of education, comparable to the A Levels in the UK, the French Baccalaureate in France or the International Baccalaureate