Difference Between JavaScript And jQuery


This article is mainly for those developers who are new to web development. People who start their careers usually question - why jQuery while there is JavaScript, or the difference between JavaScript and jQuery; which is better to use - JavaScript or jQuery; is jQuery an alternative for JavaScript, or will jQuery replace JavaScript etc?

Let us first look at what is JavaScript and what is jQuery.

What is JavaScript?

JavaScript (JS) is a dynamic programming language. It is an interpreted language. Other than the unfortunate similarity in name, it has nothing to do with Java programming language. As the name suggests, JavaScript is a scripting language.

It is most commonly used for appealing UI (like moving objects and flashy elements on the screen), user interactions (client-side validation, showing pop-ups etc.), and for controlling the document content displayed to the user.

There is nothing you need to include in the browser to support JavaScript. This is because it was considered the language of the web since its birth. It runs in all modern browsers without any additional plugins.

What do you mean by JavaScript being dynamic?

Most programming languages have dynamic behaviors. But in the case of JavaScript, pretty much everything is dynamic.

All variables are dynamic in type and existence. You declare a variable as,

var msg = "Hello World!";   

The code written in JavaScript is dynamic, you can create a variable at runtime, and the type is determined at runtime.

You can create new functions or replace existing functions at runtime.

New codes are added to the browser when more script files are loaded, and you can add any number of files at any time.

What is jQuery

The jQuery website defines jQuery (jQ) as “a fast and concise JavaScript Library that simplifies HTML document traversing, event handling, animating, and Ajax interactions for rapid web development.”.

jQuery is not a programming language instead, it is a cross-platform JavaScript library. There are many other JavaScript libraries available, like MooTools, Knockout, or even Angular (Though Angular uses TypeScript, it compiles to JavaScript at the end), and jQuery is one of the most popular among them.

jQuery is a fast, feature-rich JavaScript library. It is created to help programmers with creating a familiar UI and take care of browser compatibility issues more efficiently.

jQuery, in fact, is nothing but JavaScript. All the code you write in jQuery is converted to JavaScript internally. One line of code written using jQuery may be equal to many lines of code written using JavaScript which means programmers will have to write only lesser lines of code.

To start using jQuery on your page, you need to include one line of code in the header of your page, like,

<script src="https://ajax.aspnetcdn.com/ajax/jQuery/jquery-3.2.1.min.js"></script >   

The above line includes a jQuery library for your page using the Microsoft CDN (Content Delivery Network). The jQuery library is a single JavaScript file.

You can also include the jQuery library as a local resource from your project folder.

But there are benefits to using the CDN. If you use the minified library version, you will get the advantage of concurrent connections and multiple servers.

JavaScript Vs. jQuery

Now, we can discuss the questions mentioned at the beginning of this article. Most of those questions may arise because of the lack of a clear understanding of JavaScript and jQuery.

Since jQuery is nothing but a library of JavaScript, it cannot replace JavaScript. All jQuery code is JavaScript, but jQuery doesn’t include all the JavaScript code.

One thing you should understand is that they are not two programming languages; instead, they both are JavaScript. jQuery is just optimized to do the common scripting functions with fewer lines of code.

Lines of code

Many actions like Animate, Delay and Fade-In can be done using jQuery with very few lines of code. On the other hand, JavaScript will take lots of lines of code for the same.

We can consider a more straightforward example,

Suppose I want to select all elements having class- simple-li,

If I use JavaScript,


On the other hand, if I use jQuery,



If you check the performance of the two, you can find that plain JavaScript is faster than jQuery for accessing DOM. But JavaScript can be slower when you write some complex logic because we may make significant mistakes or use poor code, which may lead to a performance hit. On the other hand, jQuery has been tested for years to use the best and fast JavaScript codes.

In my view, it is not right to compare the two, or you cannot say one is better than the other. We need to use whichever is better suited to our requirements.

A few points to remember

A fast and concise JavaScript Library
A framework which makes event handling, animating, and Ajax interactions simpler and faster
Uses resources given by JavaScript to make things easier 
need not write much scripting which already exists in jQuery
Is a multi-browser JavaScript library that reduces the work of developers during deployment
Developers don’t have to worry about browser compatibility issues.
Need to include the jQuery library URL in the header of the page
Fewer lines of code
Suited for complex operations where developers are prone to mistakes and writing poor lines of code.

Advantages of jQuery

  • You can code the most common JS actions using jQuery with fewer lines of code.
  • Browser compatibility – you can write code that runs across browsers without having to know the various browser intricacies and won’t break.
  • It lets you write JavaScript quicker and easier.
  • It avoids common browser errors
  • Simplification of usually complicated operations – complex operations like Ajax interactions, animation, event handling etc., are handled by jQ with the best lines of code.
  • jQ is battle-tested and uses the fast and best lines of code for accomplishing most tasks.


jQuery is well suited for most applications, especially ones that need rapid development. jQuery takes care of common browser errors by ironing the fixes right into the library. jQuery also takes care of browser compatibility issues which are a developer’s nightmare during deployment.

Using JavaScript or jQuery really depends on your need and other factors. Most web development projects will work perfectly fine using jQuery. But there will be a small percentage that does require JavaScript.

Since pure JavaScript is the best-performing method of client-side development, there is a reason to use it. But a library like jQuery will help you to get to market faster and cheaper. So, it is better to depend heavily on jQuery for the initial versions of your product. Once your product is established in the marked and you have the revenues to go back and refactor the code, you can custom code all the script.