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What is JavaScript?

What is JavaScript?

JavaScript acts like the brain of webpages.

JavaScript is a programming language that adds dynamic capabilities to websites.

What do we mean by dynamic features?

Examples of dynamic functionalities include:

  1. Event Handling: An event refers to actions taken by the user on a website. With JavaScript, you can make the website respond to events like clicks, mouse-overs, and keyboard inputs. For instance, you can create an action that changes the color of a button when it is clicked.

  2. Web Form Validation: When you log in, you enter a username and password, right? JavaScript can be used to validate form data on web pages, checking whether an input is an email address or if a password is at least six characters long.

  3. Animations and Effects: You can add animations to web pages with CSS. For example, you can make a specific HTML element fade in slowly or appear after a set amount of time.

  4. Fetching & Sending Data: You can retrieve the desired data from a server that provides dynamic web content and display it on a web page, or send necessary data to the server.

  5. Creating Interactive Elements: You can create interactive elements like sliders that can be slid to the side, or dropdowns that display sub-elements below.

  6. Manipulating Webpages: Depending on specific events, you can hide or show parts of a webpage, or add content to it.


JavaScript is an essential component that, along with HTML and CSS, constitutes webpages.

JavaScript is not only used for webpages displayed in browsers but is also extensively applied in application software fields such as web servers, mobile apps, and desktop app development, making it a popular programming language.