"Software that sits between applications and operating systems, consisting of a set of services that enable interoperability in support of distributed architectures by passing data between applications. A canonical example of middleware is a message bus, otherwise known as a queue. All of the major cloud providers offer a messaging system like this, whether it is AWS Simple Queue Service, or Azure Message Queue. Queues are systems that hold data and connect systems together. They are middleware in the sense that they bridge the gap between multiple systems by passing data back and forth."
in other words
Your cloud's middleperson.