middleware

/M IH1 D AH0 L W EH0 R/
noun
  1. 1

    Software that functions at an intermediate layer between applications and operating system or database management system, or between client and server

  2. 2

    Networking software/hardware that is deployed in the middle of, as opposed to serviced by, a packet network to enhance or provide some network function, such as caching, filtering, or firewall functionality.

Source: https://en.wiktionary.org/wiki/middleware