What Is JavaScript & What Is It Used For? A Basic Guide to JS

Every page on your website likely uses JavaScript.

If you use Google Analytics, event tracking, or display ads, you’re already using JavaScript.

But you can (and should) leverage it further to create great experiences for your users. Before you can do that, you need to understand what JavaScript is and what it’s used for.

What Is JavaScript?

JavaScript (JS) is a computer programming language used to make websites and applications dynamic and interactive.

It’s unique because it can run directly in your browser, not just on a server.

Along with hypertext markup language (HTML) and cascading style sheets (CSS), JavaScript is one of the most commonly used programming languages of the internet.

In fact, 98.4% of all websites use JavaScript as of March 2023.

JavaScript, CSS, and HTML work together to make up the user-facing elements of most websites and online applications.

Think of these coding languages as the components of a house:

• HTML is the foundation of the house. It provides the basic layout, structure, and content of a website.
• CSS is the interior design. It provides design, fonts, colors, effects, and other visual elements.
• JavaScript is the electrical and plumbing systems. JS brings dynamism and interactivity to the website. For example, pop-ups, animations, video and social media embeds, drop-down menus, and many other website components are created using JavaScript.

Without JavaScript, webpages would be mostly static and boring.

JavaScript adds behavior and...