What is Wire Transfer?

Legal Definition
Wire transfer, bank transfer or credit transfer is a method of electronic funds transfer from one person or entity to another. It is an electronic payment service for transferring funds by wire, for example through SWIFT, the Federal Reserve Wire Network or the Clearing House Interbank Payments System.
-- Wikipedia
Legal Definition
Wire transfer, bank transfer or credit transfer is a method of electronic funds transfer from one person or entity to another. A wire transfer can be made from one bank account to another bank account or through a transfer of cash at a cash office.

Different wire transfer systems and operators provide a variety of options relative to the immediacy and finality of settlement and the cost, value, and volume of transactions. Central bank wire transfer systems, such as the Federal Reserve's FedWire system in the United States are more likely to be real time gross settlement (RTGS) systems. RTGS systems provide the quickest availability of funds because they provide immediate "real-time" and final "irrevocable" settlement by posting the gross (complete) entry against electronic accounts of the wire transfer system operator. Other systems such as CHIPS provide net settlement on a periodic basis. More immediate settlement systems tend to process higher monetary value time-critical transactions, have higher transaction costs, and a smaller volume of payments. A faster settlement process allows less time for currency fluctuations while money is in transit.
-- Wikipedia