Do university students have the same classmates in every class?

No. University students do not necessarily take every class with the same classmates. Enrollment can differ from course to course, and electives or courses shared across programs may include students from different years or departments. Seminars, laboratory classes, and practical courses may also assign small groups, depending on the course. Class composition varies by university, faculty, course, and academic year, so check the course-registration guide and course information.