What is Javascript and What is it Used For

Web designers and web developers use a set of coding languages to build websites however they want. The two base languages are HTML and CSS and the third is JavaScript (JS). Each code language has a purpose. HTML builds the skeleton and defines the content of a site, CSS styles the elements and specifies the layout, and JS adds interactivity to buttons, forms, and programs the behavior.

JavaScript was created by the co-founder of the Mozilla Project, Brian Eich. He created this dynamic language to be able to create interactive functions inside websites. JavaScript changes the HTML and CSS in the main code set o to create all sorts of functions… 

There is a common confusion between JavaScript and JAVA. Even though they sound similar in name, they are actually two completely different languages. Also, JavaScript is more like a nickname, since the official name is ECMAScript. Since it was created in 1997, there have been many new versions updated every few years.

For complete newbies, JavaScript can be complicated to understand. I’ll to try to explain as simply as possible what JS does, what it looks like and at the end I’ll give you some idea on where you can learn more about it. You can even take some courses to learn how to use it.

What does JavaScript do

JavaScript isn’t only used for websites. It’s also used in desktop and server programs. Some databases also use JavaScript for their programming language. Likewise, JS is used to create games. Let’s take an overview, look at what it does. When a JS script is added to an HTML and CSS build, it can manipulate lots of things. You can make elements interactive or create fillable forms with conditions and variables. But that’s just the beginning. In simple terms, here are some of the main things JavaScript can do when it’s included in an HTML and CSS code build:

  • Change HTML content
  • Change HTML attribute values
  • Change HTML styles (CSS)
  • Hide HTML elements
  • Show HTML elements

JS can do a lot more than that, but you could group it all into the above categories. The language is so versatile that changing HTML content can be something tiny to something extremely elaborate.

What does JavaScript look like

Inside the coding of a website, you will see the HTML, the CSS, and the JS. Which one is the JavaScript?

JS is always set up between <script> and </script> tags. Whenever JavaScript is added to a build, it needs to be housed within its tags so that the system knows it’s going to read that element as a JS function.

A function is a set of JavaScript code. Since JS is telling (changing) the HTML to do something different than it’s basic action, the JS snippet is called a function.

A common method of JavaScript is to use document.getElementById(demo) . This message tells the browser to find an HTML element with an Id “demo” and change it to whatever the JS is telling it to do.

There are two ways to make JavaScript readable by a browser. One is to include it inside the HTML code or to create a separate file called a .js extension. Inside the main code, the JS is set up after the HTML so that the function takes place in the right order.

In separate .js file, the functions are displayed in ‘src’ format. This means that the function is to be taken from the source file (src = source).

Learning to use JavaScript

There is no way that anyone can learn how to use JavaScript as easy as it is to use HTML. The language has many more aspects to it that need to be practiced and tested. 

I suggest that to really get a feel of what JavaScript does inside a website and how it can be used for other purposes, is to follow the W3 Schools detailed tutorial. The W3 Schools website explains every little thing about JavaScript. From the simple functions to how to use variables, statements, keywords, and much more.

Follow every tutorial at your own pace and repeat if you didn’t understand something. The key to using JavaScript efficiently is to know how the language works and when a human error is messing with the functions.


In this post, we looked at what JavaScript is in order to give you a little taste of what this coding language can do. If you are serious about becoming a web developer, JS is something you should definitely learn. I suggest you get comfortable with HTML and CSS first and then dive into JavaScript.

Once you feel like you are ready, start creating interactive forms and functions inside websites. Finally, try building a JavaScript game and show your friends how cool you are!