Difference between high school student and male student in Korean
고등학생·남학생

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.

남학생male student
남학생 means a male student, or a boy who goes to school. You can use it to talk about a boy in a class, at school, or in other everyday situations. It is a common word when describing students in simple school topics.
The difference
남학생 means a male student, so it focuses on gender. A 고등학생 focuses on being in high school.