Middleware
An IETF workshop in 2000 defined middleware as “those services found above the transport (i.e. over TCP/IP) layer set of services but below the application environment” (i.e. below application-level APIs).[3] In this more specific sense middleware can be described as the dash (“-“) in client-server, or the -to- in peer-to-peer. Middleware includes web servers, application servers, content management systems, and similar tools that support application development and delivery. Middleware - Wikipedia