Microsoft Certified Systems Engineer (MCSE) Question:

Middleware is distributed software needed to support interaction between clients and servers. In short, the software is in the middle of the Client/Server systems. In addition, it acts as a bridge between the clients and servers. It starts with the API set on the client side that is used to invoke a service and it covers the transmission of the request over the network and the resulting response.It neither includes the software that provides the actual service - that is in the server's domain nor the user interface or the application login - that is in client's domain.