There are many different ways to structure a loan.

With a standard installment loan, you borrow a sum of money for a certain period of time and repay both principal and interest at regular intervals over the life of the loan. This type of loan is fully amortizing and is common with auto loans and home mortgages.

Some loans require interest-only payments for a certain period of time, after which you must begin paying principal along with interest.

Some loans require no payments until the end of the term, at which point you pay principal and all accrued interest in a so-called balloon payment. Alternatively, some balloon loans require small payments at regular intervals and a large one at the end.

So-called demand loans do not have a specific maturity date. Instead, they are due when the lender demands them, usually with a few days notice.

Other structural details: Loans can have fixed or variable interest rates. They can be secured by an asset such as a car or home or they can be unsecured, like a credit card.