The front-end refers to the visible and interactive part of a web or mobile application that users directly interact with. This includes everything that the user sees and uses on the screen, such as layout, design, images, text, buttons, and navigation. The front-end is built using web technologies like HTML, CSS, and JavaScript. Front-end developers focus on creating a smooth, intuitive, and enjoyable user experience (UX), ensuring that the interface is responsive, accessible, and functional across different devices and browsers.

The front-end not only involves the visual aspects but also the performance and loading speed of web pages. Tools and frameworks like React, Angular, and Vue.js are used to develop dynamic and complex user interfaces. Front-end developers often work closely with UX/UI designers and back-end developers to ensure the entire application runs smoothly, providing a positive overall experience for end-users.