Money orders are tools for making payments. Think of them as alternatives to checks -- instead of writing a check, you hand over a money order. They look just like checks, and they're generally accepted (or preferred) in any situation checks are accepted.
Some people who sell online prefer or require money orders because they can be safer than personal checks (they don't bounce if they're real). However, money orders are often used in scams that take advantage of their perceived safety.
To learn more about these instruments, their pitfalls, and how to use them, see Money Order Basics.

