JavaScript

JavaScript is a programming language used to create and control dynamic content on websites, such as animations, complex interactions, real-time responses, and more.

It is one of the three fundamental pillars of the modern web, along with HTML and CSS: while HTML is used for the basic structure of a web page and CSS for style and presentation, JavaScript adds interactivity and advanced functionality.

Highly valued for creating richer and more engaging experiences for users, however, it is also a common source of site performance issues.