class vs lecture in Korean
수업vs강의

수업class
수업 means a class, lesson, or study period, usually at school. You use it when talking about having class, starting class, or what kind of class you take. It is a very common word in everyday school life.
When to use class
강의lecture
A lecture (강의) is a class or talk where a teacher or expert explains something to students. You often use this word at school, university, or for online classes. You can say you listen to a lecture, take a lecture, or talk about whether a lecture is easy or hard.
When to use lectureHow they differ
강의 is usually a lecture, especially in college or a formal talk. 수업 is the general word for a class period or lesson at school.