JavaScript is a programming language that is primarily used to create interactive elements on websites. It is executed on the client-side, which means that it runs directly on a user's computer or device within their web browser.

JavaScript was created in 1995 by Brendan Eich, and since then has become one of the most commonly used programming languages for web development. It is a high-level language, meaning that it is relatively easy for humans to read and write, and it is also designed to be flexible and adaptable.

JavaScript can be used for a wide variety of purposes on websites, including creating animations, adding interactivity to forms and buttons, validating user input, and manipulating the content on a webpage dynamically.

As a client-side programming language, JavaScript is supported by almost all modern web browsers, allowing it to be used across a wide range of devices and platforms. It can also be used in conjunction with other web technologies, such as HTML and CSS, to create robust and engaging web experiences for users.