What is JavaScript and what is it used for

JavaScript is a lightweight and versatile programming language, created in 1995 by Brendan Eich at Netscape, with the goal of making web pages interactive and dynamic. Unlike HTML, which defines the structure, and CSS, which manages the visual appearance, JavaScript handles behavior: it allows pages to respond to user clicks, update content without reloading, validate forms, animate elements and much more. It is an interpreted language, meaning that the code is executed directly by the browser without the need for compilation, making it immediate and accessible even to beginners.

Over the years, JavaScript has undergone a radical transformation, evolving from a simple tool for adding graphical effects to web pages into one of the most widely used programming languages in the world. A decisive turning point came with the introduction of AJAX in the early 2000s, which made it possible to load data asynchronously from the server, paving the way for modern web applications. Later, the arrival of Node.js allowed JavaScript to be used on the server side as well, making it possible to build entire software systems with a single language, both on the client and backend side.

Today JavaScript is natively supported by all major browsers and has a vast ecosystem of libraries and frameworks, including React, Vue and Angular for the frontend, and Express for the backend. The modern version of the language, standardized under the name ECMAScript, continuously introduces new features that make it increasingly powerful and expressive. Together with HTML and CSS, JavaScript forms the fundamental triad of web development and is considered an essential skill for any developer who wants to work on the web, whether at an amateur or professional level.