Credit's most basic definition is agreement between a lender and a borrower. The borrower promises to repay the lender at a later date—generally with interest. An example is a credit card.
Credit also refers to person's ability to pay back their debts. Credit scores and your credit report let lenders know whether or not you have good or bad credit.
You need to build your credit over time to show that you can handle the repsonsibility.
Debt is what a borrower owes to a lender. A lender can be a more than just a bank or a credit card company. You can owe money to the government, a utility company, or hospital for example. There are are many different kinds of debt a person can have:
Sometimes the lender will hire a debt collector to contact you, especially if your debt is delinquent. Being delinquent means missing or being behind on payments on an account.
Debt collectors can be a company or agency hired to recover money owed on delinquent accounts. Debt collectors are also know as collection agencies.
The Federal Trade Commission (FTC) enforces the Fair Debt Collection Practices Act (FDCPA) which prohibits debt collectors from using abusive, unfair or deceptive practices during the debt collection process.