You borrow a fixed amount of money, which you have to pay back with interest in a fixed amount of time. Interest is tax deductible. It could be secured by a mortgage on your home or by a mortgage or similar arrangement on business property. Equity financing is never secured. This becomes more common the larger your business grows.
Corporate bonds are just a form of loan.
They do not confer ownership interests on anyone. The relationship with your lender Common wisdom says that the price of equity investing is interference in your business decisions by outside investors. Common wisdom says this doesn't happen with lenders. The fact of the matter is that lenders quite often impose conditions on their loans. The difference is that loans come to an end at a specific time, so it might be easier to take.