The terms frontend and backend are used in various places in information technology in connection with a classification of shifts. Typically, the frontend is closer to the user, the backend closer to the system. In some cases, this interpretation is not applicable, but the principle is that the frontend is closer to the input and the backend is closer to the processing.
In the case of client-server applications, the program running on the client is referred to as the frontend (i.e. in this case: service user), and the program running on the server is referred to as the backend (here: service provider).
In database applications, the graphical user interface, consisting of forms and reports, is referred to as the frontend, and the tables, views, stored procedures, etc., are referred to as the backend.
Frontend, closely related to the above meaning, also basically refers to the user interface, which can be implemented, for example, in the form of a graphical user interface (GUI) or by means of screen masks.
In web-based application systems with separate user interfaces for regular users and system administration, the term front-end refers to the Internet pages that are accessible to the public, while the term back-end is used to refer to the area accessible only to the limited group of users.
Software is often divided into frontend and backend, with the backend being closer to hardware. For example, the KDE-based program K3b for burning CDs and DVDs is a pure frontend that uses various console programs (e.g., cdrkit or MoviX) as the backend. This classification can be multi-layered, i.e. a backend can itself be divided into a frontend and a backend at a lower level of abstraction.
In compilers, the translation of the program code into binary code is often done in two steps, using a general intermediate code that is independent of the hardware. The first translation step is referred to as the frontend, the second as the backend.
In the Unix printing system CUPS, the module that sends the processed raw data to the printer is called the backend. For example, there are backends for parallel interface, network, USB, etc. A CUPS frontend is a graphical user interface for CUPS.
In speech synthesis, speech is often generated from text via an intermediate step (a symbolic phonetic representation), with the first translation step representing the front-end and the second the back-end.
In content management systems (CMS) such as WordPress, the administration interface for creating and maintaining content is often referred to as the backend, while the website generated by the CMS is considered the frontend.