middleware

Definitions

1. Software that functions at an intermediate layer between applications and operating system or database management system, or between client and server.
   uncountable, usually
2. Networking software or 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.
   uncountable, usually

Equivalents

CEFR level