Having a basic understanding of the education sector concepts will make you feel more comfortable and confident when you research and make your research easier to complete because you do not have to do additional research to understand the concept.
The UN developed a comprehensive framework of internationally agreed definitions to compare different education systems and their curricular content. The ISCED 2011 is the last major revision of this framework. Since then, the UNESCO-UIS has continued to make minor revisions in consultation with UN member states and international organizations. The table below shows the coding schemes for educational programs and educational attainment. To read more about ISCED, its education definitions, and classifications, read this document.
https://lh3.googleusercontent.com/n-EXk3pPQx6t0zYCdnDyYlMHbU_m4zhtFOXCPAO7jG-fkBbv4adtgNT2XBOaP3OZ4lZjF6JZikhFHA_yXM9iVVvEL3I87C-3ReRCpurPwiXw4h9d0u_RCtWLwllYFVmhPM0awUYvDP-VVqM5TSxyMQ
The image below shows the US education system classified according to ISCED.
https://lh6.googleusercontent.com/e1FEG6JRPapmZwYoVw3-W9xHMg_LiREMKOo0gZWOxH6RPI0K0oxaHPdZVDRU-n4xwaCW151nMseXRbMNImNx6dEo9Hg5kutVIJ0a8rPgg5EOQSv_4s6RkBBP72YA3aV9g4ww4TpKWhPffhsQiQl1ow
Primary education is also referred to as elementary education or basic education. This level of education is often designed to teach “fundamental skills in reading, writing and mathematics (i.e. literacy and numeracy) and establish a solid foundation for learning and understanding core areas of knowledge, personal and social development, in preparation for lower secondary education.” This level of education can range from 4-7 years. Children enter at ages 5-7years and complete it at 10-12 years. Read more about this here and here.
Secondary education is usually divided into lower secondary and upper secondary. There are, however, systems where there is no division. Here the entire system is referred to as secondary schools.
The lower secondary school is also referred to as junior secondary school, middle school, or junior high school. This level of education aims to lay the foundation for lifelong learning and human development. It is organized around a more subject-oriented curriculum and introduces theoretical concepts across various subjects. Students typically enter this level between ages 10 and 13 (age 12 being the most common).
The upper secondary school is also referred to as secondary school (stage two/upper grades), senior secondary school, or (senior) high school. This level builds on the education provided in lower secondary education and prepares the student for tertiary education or provides skills relevant to employment, or both. The instruction at this level is more varied, specialized, and has greater depth. Students typically enter between ages 14 and 16 and complete it around 17 or 18.