Back-end

[Sommer]

Back-end refers to the server that hosts a websites backend services such as database management, authentication and authorization. The back-end server is responsible for handling requests from the front-end web application and processing them in a reliable, efficient manner. It is also responsible for storing and retrieving data from the database.

[Ernesto]

The rear, back, or unseen portion (of something).

[Luis Fok]

Relating to the back end part of a hardware or software system.