[1] MSMQ is a messaging protocol that allows applications running on separate servers/processes to communicate in a failsafe manner.
A queue is a temporary storage location from which messages can be sent and received reliably, as and when conditions permit.
By contrast, sockets and other network protocols assume that direct connections always exist.
Microsoft also has incorporated MSMQ in its messaging technology framework, Windows Communication Foundation (WCF).
Under WCF, MSMQ can be used for providing secure, reliable transport with a unified programming model compatible with other communications standards.