Bootstrap is a popular open-source front-end framework for developing responsive and mobile-first websites and web applications. Bootstrap provides a collection of pre-designed components, such as buttons, forms, navigation bars, grids, tables, or cards along with CSS and JavaScript tools for layout and interactivity. This allows developers to quickly and easily create visually appealing and consistent user interfaces across different devices and screen sizes.

Bootstrap includes JavaScript plugins without jQuery. Developers can make toggleable hidden elements, modals and offcanvas menus, popovers and tooltips. Nearly all of Bootstrap’s JavaScript plugins feature a first-class data API, allowing you to use JavaScript just by adding data attributes. Bootstrap offers a dozen plugins that you can drop into your projects.

Installation

You can install Bootstrap’s source Sass and JavaScript files via npm, RubyGems, Composer, or Meteor. 

npm install bootstrap

or

npm install bootstrap@latest

Example

<div class="card" style="width: 18rem;">
  <img src="..." class="card-img-top" alt="...">
  <div class="card-body">
    <h5 class="card-title">Card title</h5>
    <p class="card-text">The card's content.</p>
    <a href="#" class="btn btn-primary">More details</a>
  </div>
</div>

For more information, you can visit https://getbootstrap.com/.