College Scholastic Ability Test or CSAT (Korean:대학수학능력시험 also abbreviated as 수능) is a type of standardized test used by South Korean universities for determining admission.
My Korean mentor is tutoring a high school student for his CSAT. The subjects are Korean, Mathematics, English Language, Social Science/Science and Foreign Language/Hanja.
Hagwon (학원) is a for-profit private institute, academy or cram school. Three students from my Korean Digital Academy class are teachers at 학원. Due to the preference for having native English speakers teach English, many native English-speaking college graduates are hired to teach at hagwon in Korea.