Frontend

In short: The frontend is the part of an application that users see and operate.

In more detail: For web pages it runs in the browser: HTML for content, CSS for appearance, JavaScript for behaviour.

In Depth

Tasks

Display, input, validation, accessibility, reacting to screen sizes. Often with frameworks such as React, Vue or Angular.

Counterpart

The backend delivers data and logic. Both talk via an API. See presentation tier, UI, UX.

See also: Backend, API, UI, UX