Bootstrap is an adaptive UI framework for websites. It, like many other UI frameworks for web development, is a set of CSS classes, UI components and jQuery plugins. Bootstrap is considered a lightweight framework. In other words, it uses CSS more than JavaScript to do its job. Even though Bootstrap is considered lightweight, a web page that uses Bootstrap’s toolkit still requires more processing to render compared to a page written specifically for this form factor. For this reason, performance should be an important factor when designing, developing, and testing pages that utilize any part of the Bootstrap framework.
If you prefer to use the latest versions of Bootstrap and jQuery, update your project with NuGet.
Bootstrap does a lot of things for you automatically. It also makes it easy to adapt the default behavior for a specific form factor, while keeping your page looking good on other form factors. Bootstrap version 3 comes with CSS classes specifically targeted to the screen sizes that mobile, tablet, desktop browsers and even PC browsers with very large screens deal with. You can use Bootstrap’s CSS classes to annotate HTML5 elements. Among the most commonly used CSS classes is Bootstrap’s grid system, a set of classes that organize the layout of a page using rows and columns. I’ll describe this system in more detail later in this article.
Bootstrap has a number of UI components for creating a site’s UI, including the Button dropdown, Button group, Dropdown, Navbar, Breadcrumb, Media object, Pagination and Progress panels, and many others. Most of these components are themselves adaptive, i.e. they are rendered differently depending on the screen width supported by the browser. For example, Navbar is a powerful component that automatically transitions from a full-width menu bar on desktops that shows menu items to a nice-looking compact version that provides menu items via a drop-down menu bar activated by tapping Navbar.
To support more advanced UI tools, Bootstrap also includes a set of custom jQuery plugins, including Carousel, Collapsible panel, Modal dialog prompts and Popover messages.
