Front and back ends

In software engineering, front end and back end distinguish between the separation of concerns between a presentation layer (the front end) and a data access layer (the back end).

The front end is an interface between the user and the back end. The front and back ends may be distributed among one or more systems.

In software architecture, there may be many layers between the hardware and end user. Each can be spoken of as having a front end and a back end. The front is an abstraction, simplifying the underlying component by providing a user-friendly interface.

In software design, for example, the model-view-controller architecture provides front and back ends for the database, the user and the data processing components. The separation of software systems into front and back ends simplifies development and separates maintenance. A rule of thumb is that the front (or "client") side is any component manipulated by the user. The server-side (or "back end") code resides on the server. The confusion arises when one must make front-end edits to server-side files. Most HTML designers, for instance, don't need to be on the server when they are developing the HTML. Conversely, the server-side engineers are, by definition, never on anything but a server. It takes both to make a functioning, interactive website.