What is the primary purpose of JavaScript in web development?

JavaScript plays a central role in web development, primarily by adding interactive behavior to web pages. This interactivity can include responding to user inputs, modifying HTML and CSS dynamically, and enhancing the overall user experience on a website. Features like form validation, creating dynamic content updates without needing to refresh a page, and building responsive animations are all accomplished through JavaScript.

In contrast, other functions such as structuring content are primarily the domain of HTML, while styling web pages falls under CSS. Managing databases typically requires server-side languages or scripts, not JavaScript, which primarily operates in the client-side browser context. Thus, JavaScript’s distinguishing advantage lies in its ability to create engaging and interactive user interfaces, making it essential for modern web development.