There are two kinds of certificates: minor and double degree. Minor is minor certificate and double degree is degree certificate. The value of minor certificate is relatively low, similar to elective courses. A double degree certificate is equivalent to the degree certificate you got after your major graduation. Double degree needs to complete all professional courses and add graduation thesis, and only minor in some major professional courses. Minors only need full credits, simple exams, and no papers and defenses. In terms of difficulty, minor is the simplest of the three. A minor degree is an extra course for students at school. You can get the diploma and degree certificate issued by the school, which is helpful when looking for a job, but the institution still employs with the first degree (undergraduate).