When you buy something on credit, you borrow the money from a lender and put yourself in debt. The paperwork documenting this transaction is a debt/lending agreement. For example, simple debt / lending agreements are used to finance RV or boat purchases. More complicated debt / lending agreements for commercial business operations may include complex credit agreements, promissory notes, security and guarantee agreements, subordination or inter-creditor agreements, patent or trademark collateral security agreements, assignment and assumption agreements, hazardous substance indemnity agreements, mortgage agreements, and accounts receivable letters. When substantial amounts of money are involved, you'll want to use a business attorney with experience in negotiating and drafting debt and lending agreements.