What is one difference between a vocational school and on-the-job training?

What is one difference between a vocational school and on-the-job training?
a. a vocational school degree takes one year to earn. on-the-job training takes two or more years.
b. a vocational school degree takes weeks or months to earn. on-the-job training takes two years or fewer.
c. a vocational school is usually paid for by the worker. on-the-job training is usually paid for by the employer.
d. a vocational school is usually paid for by the employer. on-the-job training is usually paid for by the worker.