UPDATED BY
Matthew Urwin | Feb 01, 2024
REVIEWED BY

JavaScript is a critical tool in web development. While CSS and HTML provide web pages with static content, including the style and structure that appear on the page, JavaScript enables dynamic changing of these contents and enriches the user experience with advanced, interactive features.

 

What Is JavaScript?

JavaScript is a programming language that enables web developers to make static content dynamic, resulting in a more engaging site experience for users. By manipulating HTML and CSS elements with JavaScript, developers can produce shifting background colors, dropdown menus, video embeds, pop-ups and other interactive elements. 

Developers can perform a range of tasks with JavaScript because the language comes with many libraries and frameworks. In programming, a library is a collection of prewritten code that allows developers to automate actions, while a framework is a collection of libraries and other tools that serve as the foundation for websites and applications. Below are a few of the libraries and frameworks developers use to tailor JavaScript to their needs:

  • Node.js 
  • React.js
  • Express.js
  • Vue.js
  • Angular
  • Redux
  • Axios   

 

Why Is JavaScript Used?

JavaScript allows developers to create unique, client-side scripts that enable the dynamism and interactivity of web elements. Developers can also write server-side code in JavaScript through the use of cross-platform engines like Node.js. Some basic examples of JavaScript at work include playing and pausing video embedded on a page and activating drop-down navigation menus. 

Developers often use front-end frameworks, such as React, Angular and Vue, when building web and mobile applications to reduce programming time and potential errors by importing prewritten code that executes common functionalities and components. These frameworks contain collections of code libraries that developers can use to streamline their workflow by reusing code that others have already created. Frameworks allow applications to remain manageable when scaling up while increasing collaboration between developers.

Related Reading From Built In ExpertsNode.js App Security: Let No One Through the (Digital) Gates

 

How Is JavaScript Different From Other Programming Languages? 

Many developers rely on JavaScript to build websites due to several key advantages it offers: 

  • Quicker development: JavaScript is a dynamically typed language, meaning variables can have any data type. Developers then don’t have to assign a specific data type to variables, accelerating the development process.   
     
  • Greater flexibility: As an object-oriented language, JavaScript stores data and functions in objects, which can be altered and receive different properties from other objects to perform complex actions. Other languages are procedural, requiring developers to follow strict instructions. 
     
  • Easy accessibility: Many programming languages must have their code compiled into machine code before developers can access it. JavaScript doesn’t need its code to be compiled nor does it require installations, making it easier to work with for developers.
     
  • Enhanced problem-solving: JavaScript treats functions as first-class citizens, so developers can rearrange and repurpose small blocks of code. This makes it possible to solve more complicated problems like manipulating objects.
      
  • Improved user experience: Because JavaScript uses first-class functions, it can leverage these functions to respond to events. A user performing an action on a site may trigger a corresponding function, leading to a more interactive user experience.
     
  • Broader versatility: JavaScript operates directly in web browsers to help make websites engaging for users. But developers can also combine JavaScript with different libraries and frameworks to complete more advanced back-end applications.   

 

Is JavaScript Front-End or Back-End?

JavaScript is used across the entire web development stack, meaning that it has both front-end and back-end applications. That said, JavaScript is most commonly recognized as a front-end programming language dedicated to adding interactivity to web and mobile apps.

JavaScript has a wide range of back-end development applications as well. One of the most popular JavaScript runtime environments is Node.js, which can be used to build web servers and develop back-end infrastructure. By using Node.js, back-end developers can create support for data updates from the front end, read front-end data, delete front-end data and build scalable network applications.

Likewise, frameworks such as Express, which is based on Node.js, can be helpful for the back end. Developers can also use frameworks such as Next.js, Gatsby and Meteor for back-end development, depending on use cases. Express is useful for building web servers; Gatsby is a front-end framework used for generating static web pages; Next and Meteor are full-stack frameworks that can accomplish front- and back-end development of the same technique through server-side rendering, which improves response time.

Learn JavaScript — Full Course for Beginners. | Video: freeCodeCamp.org

 

Is Python Better Than Javascript?

JavaScript remains the more popular programming language with many advantages, but Python presents other advantages that JavaScript lacks. In the end, which language is better depends on a website’s particular needs.

Python generally presents less of a learning curve than JavaScript for those early in their programming careers. Where Python falls short, however, is in its scalability. Python does not support asynchronous programming, but Node.js does. This means JavaScript can handle a large number of users as well as large volumes of data with minimal server usage. Python is only able to accomplish cooperative multitasking through the use of co-routines.

Ultimately, whether Python or JavaScript is better for development depends on your project’s functionality and purpose, as well as your own particular skill set. For example, a front-end developer may be able to use JavaScript on the back-end as well without constraints, but if the application or website requires machine learning features, Python is preferable due to the numerous libraries available to reduce programming workflows and ensure functionality.​

 

Frequently Asked Questions

What is JavaScript used for?

JavaScript is often used to develop interactive content for websites like pop-up windows, video embeds and dropdown menus. However, developers may also use it on the back end to build site infrastructure and more complex applications.

How long does it take to learn JavaScript?

Those with a tech background may be able to learn JavaScript in as little as two weeks. However, those with no technical knowledge may take up to six months to learn JavaScript.

Expert Contributors

Built In’s expert contributor network publishes thoughtful, solutions-oriented stories written by innovative tech professionals. It is the tech industry’s definitive destination for sharing compelling, first-person accounts of problem-solving on the road to innovation.

Learn More

Great Companies Need Great People. That's Where We Come In.

Recruit With Us