A synchronous process is invoked by a request/response operation, and the result of the process is returned to the caller immediately via this operation.
An asynchronous process is invoked by a one-way operation and the result and any faults are returned by invoking other one-way operations. The process result is returned to the caller via a callback operation.
For example, you can think of a synchronous process as a telephone, and an asynchronous process as the postal system. When you are having a conversation on the phone, you send and receive messages instantaneously using the same connection. If you were to send the same message in a letter via the postal service, it would be delivered in one manner, and its response returned in another.
An asynchronous process is invoked by a one-way operation and the result and any faults are returned by invoking other one-way operations. The process result is returned to the caller via a callback operation.
For example, you can think of a synchronous process as a telephone, and an asynchronous process as the postal system. When you are having a conversation on the phone, you send and receive messages instantaneously using the same connection. If you were to send the same message in a letter via the postal service, it would be delivered in one manner, and its response returned in another.