A wire transfer is an electronic transfer of money. In a traditional wire transfer, the fund goes from one bank or credit union to another using a network such as SWIFT or Fedwire. But the term wire transfer has other types of transfers in its purview.
Giro transfer is a payment transfer method from one bank account to another bank account and initiated by the payer, not the payee.
A money order is a payment order for an amount of money which is pre-defined. As it is required that the funds be prepaid for the amount shown on it, it is a more trusted method of payment than a check.