Consolidation means you are simply combining existing loans. Your total payment amount and total interest will likely remain the same, but you’ll have the convenience of making one payment rather than multiple payments. This type of loan is usually associated with federal government student loans.
When you refinance, you are taking out a single new loan to pay off your old ones. You’ll probably have a new interest rate, new terms, and a different monthly payment amount. This is the loan solution offered by your credit union.