Wired funds are monies that pass directly from one financial institution to another financial institution using the Federal Reserve’s Fedwire system.
ACH transfers are similar to an electronic check and use a “batch” system of payment. The batch system means that instead of each transaction being handled individually as in a wire transfer, all the ACH transfers are sent to a centralized clearinghouse, held for a period of time, and then sent to the receiving bank at once in a batch. This means that multiple transactions are processed simultaneously once or multiple times a day, depending on the bank.
Wire transfers are generally more expensive than ACH transactions, many of which have no additional cost associated with them. However, ACH transactions can take longer to process, because of their batch characteristics and they are less secure than wire transfers. The identities of both the initiating and receiving parties to a wire transfer are generally verified, making a wire much harder to “fake.”