What is JavaScript?

Whenever a webpage delivers an interactive element, you can usually bet that JavaScript had something to do with it. The third layer of core web technologies, after HTML and CSS, JavaScript was developed to add behaviour to websites. From drop-down menus to image carousels and videos, JavaScript completely changed how we use websites.

I’m new here…tell me about JavaScript for beginners

JavaScript (JS) is a dynamic scripting and programming language that lets developers add interactive features to web pages. It has object-oriented capabilities and communicates with the client-side script, to show more complex outcomes to the user.

It was first introduced in 1995 by Netscape 2.0, though back then it went by the name Mocha. Not long after a Mocha prototype was introduced into Netscape Communicator, it was renamed to LiveScript. The reason? LiveScript was better for marketing.

JavaScript elevates static HTML web pages to something more. It makes changes to a page without the need for a manual reload.

What are the benefits of JavaScript?

There’s a lot we wouldn’t be able to do without JS, and it’s used in applications all over the web. But in addition to improving the online user experience, JavaScript is full of benefits that make developers fall in love with it just a little bit more.

  • Client-side JavaScript is fast because it can run straight away within the client-side browser. There’s also no need to compile code before running it because all major browsers support the JS compilation.
  • Learning and implementing JavaScript is relatively straightforward. Its syntax is simple compared to languages such as C++.
  • JavaScript complements many other languages well, streamlining the creation of a wide variety of products.
  • The language creates richer interfaces and enhanced functionality of web pages, keeping users engaged for longer.
  • There’s lots of versatility to enjoy, with multiple ways to use JavaScript through Node.js servers.

Vocab check-in!


Node.js is a run-time environment built on Google’s V8 JavaScript engine. It’s made to create scalable network applications, giving developers a tool to create real-time websites with push capability.

Common uses of JavaScript

The interactive possibilities through JavaScript are virtually endless. Just some of the ways developers can add behaviour to web pages

  • Animated graphics
  • Dropdown menus
  • Autocomplete form suggestions
  • Buttons that change colour when a user hovers over them
  • Interactive forms
  • Photo carousels
  • Zooming in and out of images
  • Playing audio or video

But JavaScript doesn’t stop there. Developers can also use JavaScript frameworks (libraries of code) to build web and mobile apps. JavaScript is also a handy tool in building simple web servers and even creating browser-based games. Oh – and it can be used to fly drones.

JavaScript, HTML & CSS: A match made in heaven?

JavaScript, HTML and CSS work together as three building blocks of the world wide web. While HTML is responsible for creating objects, CSS
provides the formatting, and JavaScript lets you manipulate those objects.



HTML is the abstract stuff behind a web page, such as images and text. It defines the content and basic structure of a website through HTML tags.


CSS controls how that content is displayed, adding style and structure (and pazzazz).


JavaScript impacts the behaviours of HTML and CSS items, so users can interact with the browser.

Together, they form the basis of any web developer’s journey.

Let’s break down variables, numbers & strings

Some key terms you might come across when learning about JavaScript are variables, numbers and strings. But what do they all mean and what’s their significance in the JS language?


JavaScript variables are the containers used for storing data values, which can be changed. They can contain anything from numbers through to complex data and entire functions. They are divided into local variables (declared only inside a block or function) and global variables (accessible from any function).


JavaScript solely uses one type of number, which can be included with or without decimals. In the JS language, a number can keep to around 17 decimal places for a good – but not perfect – level of precision.


JavaScript strings are used to store and manipulate text and are written within quotation marks. A string is simply a series of characters that a script will interpret literally, and is useful to hold data that is represented in the form of text.

Can anyone learn JavaScript?

Learning JavaScript comes after HTML and CSS. It goes a step beyond fundamental web development skills, but most people will be able to learn JS in a matter of months, up to one year. While it’s not the most complicated programming language on the market, it’s certainly not the easiest, either.

Through a combination of books, online and in-person classes, and online courses, you will eventually get the hang of the language.

JavaScript frameworks contain comprehensive collections of pre-written code that you can use to build basic, repetitive functions. This method is far easier than coding each from scratch and can speed up development by skipping over the more simple elements and getting straight to the complicated parts of a website.

Some of the major companies said to have JavaScript firmly in their tech stack:

  • UBER
  • EBAY

Our Yolkers have this covered

JavaScript is everywhere, powering the smallest of websites through to the largest tech companies on the planet. When the only real limit is your imagination, what could your business achieve with a JavaScript expert on your team? Our Yolkers can bring that interactive element to your website, keeping it engaging, innovative, and attractive to a modern-day audience.