What is "asynchronous operation"

n. operations that occur without a regular or predictable time relation to other events [ant: synchronous operation]

In telecommunications, asynchronous operation or asynchronous working is where a sequence of operations is executed such that the operations are executed out of time coincidence with any event. It can also be an operation that occurs without a regular or predictable time relationship to a specified event; e.g., the calling of an error diagnostic routine that may receive control at any time during the execution of a computer program.