A promissory note is best described as:

A promissory note is best described as a promise to pay, which is essential to understanding its role in financing and loans. In essence, it is a written, unconditional promise made by one party (the maker) to another (the payee) to pay a sum of money at a specified future date or upon demand. This agreement includes details such as the amount owed, interest rates, and the payment schedule, making it a fundamental document in transactions involving borrowed money or financing.

Understanding this concept is crucial in real estate transactions, as promissory notes are often used in conjunction with mortgages and purchase money loans. Recognizing this helps in distinguishing it from other options: a security interest pertains to collateral for a loan, a conditional contract involves an obligation dependent on a specific event, and an affidavit is a written statement confirmed by oath, which does not pertain to payment obligations. These differences underline why describing a promissory note as a promise to pay captures its essence and legal significance accurately.