If you are creating a web site for the first time, then you probably have some knowledge of the HTML programming language. HTML is a fairly simple language to learn, and most beginning web designers are usually self-taught when it comes to using HTML to create a simple site. HTML provides the style, structure, and formatting for a web site.
However, HTML does not actually do anything. It is a static programming language. It does not process anything or make your site interactive, it just sits there and tells the browser how the site should look. So, other programming languages have been created to not only improve site design, but to validate forms, establish cookies to make sites easier to use, and to react to input received from the user.