Introduction to JavaScript

JavaScript is a scripting language and one of the main building blocks of the web—along with HTML (that’s the structure) and CSS (the style stuff). It’s used to create almost anything you see on the web, from simple animations to full-on web apps that handle and process data, payments, and pretty much any feature you can think of.

When you're making a web app, you usually need all three—HTML, CSS, and JavaScript. Think of it like building a house: HTML is like the walls and floors, CSS adds the paint and decorations, and JavaScript? That’s the part that brings it to life—like water, electricity, and lights. Without it, the house kinda just sits there doing nothing.

Client-Side vs. Server-Side JavaScript

So which is which, and how does the role of JavaScript differ depending on the goal? (For example, is it the same to create animations in JavaScript as it is to process payments?) Well, it isn’t. Websites and web apps are generally split into two parts: client-side and server-side. So what’s the difference between the two?

  • Client-Side JavaScript: Client-side is the user side, which means the browser. JavaScript for browsers is used to create and enable interactive features—like getting real-time updates, loading data without refreshing the page, showing a popup when a button is clicked, or reacting to user scroll. It’s basically what happens inside the user’s browser.
  • Sever-Side JavaScript: On the other side this JavaScript runs on the server. It handles the behind-the-scenes stuff that doesn’t directly involve the user. For example, getting and preparing the data from database, handling user authorization and authentication, or processing payments. This JavaScript runs using special runtime (not a browser) that runs and executes the JavaScript on the server, these run times include but not limited to, NodeJS, Deno and bun.

Why should you learn JavaScript?

Nowadays, JavaScript is used for almost everything in the tech industry. Whether you’re building web apps/websites (both client-side and server-side), mobile apps, or even desktop apps. So learning JavaScript is a key skill for getting into the tech industry and opening many opportunities for you.

  1. 1
    JavaScript is the most widely-used language in web development for its versatility—building frontend using vanilla JavaScript or frameworks such as React, Vue, and Angular, and backend using runtimes such as NodeJS and frameworks like NestJS. It also provides a wide range of frameworks for creating mobile apps, like React Native. So it gives you all the tools to rapidly build apps.
  2. 2
    JavaScript has a strong developer community. It has a rich and active community which makes it easy for beginners to learn JavaScript, solve problems, and sharpen their skills fast.
  3. 3
    JavaScript also offers career opportunities, as it's a pivotal skill for full stack developers. And it is high in demand in the market.

JavaScript in Action: A Simple Example

To give you a real example of what JavaScript can do, here’s a very basic line of JavaScript code that execute to display a message "Welcome to JSBites!" to the user who open the page:

javascript
          alert('Welcome to JSBites!');

This code triggers an alert box in the browser with the message 'Welcome to JSBites!'. a small but powerful demonstration of how JavaScript interacts with the user.

Also, there are more wonderful tools to help you show your content in a better appearance. We will cover it another time.

Where Can You Use JavaScript?

Web browsers is not the only place that JavaScript can be used in. Also, It can be used with variant ideas and across different platforms, for example:

  • Web Browsers: The most common and main place to use JavaScript is to add interactivity to websites. It is also the first platform that developers start learning JavaScript on.
  • Servers: When you start learning and using Node.js, you can use JavaScript on the server side for backend development.
  • Mobile Applications: Some frameworks like React Native give developers the ability to create mobile applications using JavaScript.
  • Game Development: JavaScript, using libraries like Phaser, is also used to build browser-based games/online games.

How to Get Start with JavaScript?

To start coding in JavaScript, all you need is a modern web browser and a text editor. In our course, we’ll offer you a great guide through setting up your first project, writing basic scripts, and linking them to your HTML page also that will be fully free.

Conclusion

After this interesting introduction about JavaScript, you can notice the importance of JavaScript and also will be very convinced that JavaScript is really a must-have skill for anyone looking to enter the web development world. With its vast abilities and easy integration into modern web browsers, it’s an essential tool for creating interactive web experiences. Throughout this course, you will build a solid foundation in JavaScript and start creating dynamic web applications.