A hagwon is a private educational institution in South Korea that offers supplementary classes to students. These schools focus on various subjects, including English, math, and science, and are popular among parents seeking to enhance their children's academic performance. Hagwons operate outside the regular school system and often have flexible hours, allowing students to attend after their regular school day. They can vary in size and quality, with some offering specialized programs or intensive courses to prepare students for exams like the CSAT (College Scholastic Ability Test).