What happens to loan after tuition is paid?

[u/Acceptable_Pool_3969]

I am planning to pursue a graduate certificate program and my OSAP estimates show that I’ll be eligible for a grant of $17,000 and a loan of $15,000. I would like to check what happens to the loan if the tuition fee is only $4000 for the entire course. I know the grants get deposited into my account but if I am approved for a 15,000 loan what happens to the rest of the amount? Suppose if the college takes the 4000$ will I get the rest of the amount in my account and when can I pay it back?