What is Bootstrap ?

Bootstrap-4 is the most popular HTML, CSS, and JavaScript framework for developing responsive, mobile-first web sites. JavaScript is a coding language used for Front End and nowadays used for Back End development. It is used in conjunction with HTML & CSS. Bootstrap is a User Interface UI Framework that has been developed using HTML, CSS and JavaScript.

Note :- Bootstrap 4 is the newest version of Bootstrap.Bootstrap 4 supports the latest, stable releases of all major browsers and platforms. However, Internet Explorer 9 and down is not supported.

Bootstrap is a free and open-source front-end web framework for designing websites and web applications. It contains HTML- and CSS-based design templates for typography, forms, buttons, navigation and other interface components, as well as optional JavaScript extensions.

What is the bootstrap CDN ?

Bootstrap CDN is a free and public content delivery network. Users of Bootstrap CDN can load CSS, JavaScript and images remotely, from its servers.Bootstrap uses Max CDN's global content delivery network, which makes websites using its service resilient to unexpected surges in web traffic.

How do you link a Stylesheet in HTML ?

To start with, open up your html document in Sublime Text. In the header section, add: <link rel="stylesheet" type="text/css" href="path of your css file">. You want to change "path of your css file" with the path to the css file you are trying to link the html page to.

Example :

<link rel="stylesheet" type="text/css" href="">

Script File link HTML

<script src=""></script>
<script src=""></script>
 What is responsive website ?
Responsive Web design is the approach that suggests that design and development should respond to the user's behavior and environment based on screen size, platform and orientation. The practice consists of a mix of flexible grids and layouts, images and an intelligent use of CSS media queries.

Example :- You can open the same website in the desktop and open the same website in mobile or tablet too. It will be fully open in both. 

In Desktop
In Desktop

Example: In Mobile or table mention below