A more thorough explanation:

A promissory note is a written promise to pay a specific amount of money to a named person or the holder of the note. The person who makes the promise is called the maker of the note.

For example, if you borrow money from a friend and promise to pay them back in a month, you could write a promissory note that says:

"I promise to pay [friend's name] $100 on [date] for the money I borrowed."

You would sign the note, and your friend would hold onto it until you pay them back.

Another example of a promissory note is when a company borrows money from a bank. The company would write a note that promises to pay back the loan with interest by a certain date. The bank would keep the note as proof of the loan.

Overall, a promissory note is a legal document that shows a promise to pay back money. It must be in writing and signed by the person making the promise.