Definition: A money order is an alternative to cash and much safer, because it can be replaced if the money order is lost, stolen or damaged. This is an important consideration when one needs to carry large sums of money.
Money orders are recommended and a secure way to paying rent--unlike personal checks--because the recipient is guaranteed payment. Money orders are issued by the US Postal Service and can be obtained from any US post office.
For more information, please check out the information on money orders from the US Postal Service.