JavaScript is a programming language that allows developers to create interactive web pages. It's a core technology of the World Wide Web and is used to add interactivity to websites. Some examples of JavaScript in action include: Image carousels, Click-to-show dropdown menus, Dynamically changing element colors, Animated 2D and 3D graphics, and Database-driven apps.
JavaScript is so versatile that you can use it to easily add cool design elements such as animation, interactive maps, and scrolling video. Organizations and clients want web designers who can not only put together a technically sound page but one that also will lure visitors. If you know JavaScript, you can deliver.
Like we mentioned earlier, HTML creates and structures the website's content, CSS adds style and formatting to these structures, and then JavaScript turns those stylized components into something that a user can interact with.