Elective courses are more flexible than required courses.
Tips
usage
Always pairs in opposition with 必修课 (bìxiūkè, required course). Universities further split 选修课 into 限选课 (xiànxuǎnkè, restricted electives: must pick from a specified list) and 任选课 (rènxuǎnkè, free electives: pick anything).
