Difference between high school student and college student in Korean
고등학생·대학생

고등학생high school student
The word (고등학생) means “high school student.” You use it for someone who goes to high school, usually a teenager. It is a common everyday word when talking about school life, family, or future dreams.

대학생college student
A college student is a person who studies at a college or university. In Korean, 대학생 means someone who goes to university after high school. You can use this word to talk about yourself or another person in daily life.
The difference
A 대학생 studies at a university, not a high school. They are usually older than a 고등학생.