'Many of these products are similar in nature and often depend on the issuing bank.
Cashier's Check Are checks signed and guaranteed by the bank. This means the funds are coming from the bank instead of your account -- which usually means they immediately take the money from your account. This is usually the most secure of the options and usually doesn't have many restrictions.
Certified Check Are checks signed by the customer, certified by the bank that you have enough funds and that your signature is genuine. Usually, but not always - the bank will set aside the funds.
Bank Draft Similar to a certified check but the bank will set aside the funds until the bank draft is used. Generally used in transactions involving larger sums.
Money order It's a payment order similar to a certified check; however, it needs to be prepaid. Also money orders may have maximum face values'