Front-end, also known as client-side development, refers to the part of web development that deals with the user interface and user experience of a website or application. It involves the design, development, and implementation of the visual and interactive elements of a website or application that users see and interact with.

Front-end development typically involves using web technologies such as HTML, CSS, and JavaScript to create web pages that can be rendered in a web browser. Front-end developers work to ensure that web pages are responsive, accessible, and user-friendly across a range of devices, including desktops, laptops, tablets, and smartphones.

Front-end development often involves collaboration with designers, back-end developers, and other stakeholders to ensure that the user experience is consistent with the overall brand, and that the website or application is easy to use and navigate.

Some popular front-end development frameworks and libraries include React, Angular, Vue.js, Bootstrap, and Materialize.