The advantages of retained earnings is that the company does not have to pay the money back, and they are not required to pay interest, rather than retained earnings.
On the other hand, the disadvantages of retained earnings might make the company has insufficient funds.The loan can be acquired for the long term and for the short term purpose. The fixed repayments are spread over a period of time that can be good for budgeting. The disadvantage of taking the loan is that it might hold high interest rate that may have to bear by the business