Bootstrap components are a collection of optional jQuery plugins which bundled with Bootstrap.

The purpose of Bootstrap components is to provide extended features and capabilities which would be difficult (or impossible) to accomplish without the use of Javascript. Some components provide are purely functional, whereas some components are used to define functionality for some of Bootstrap's special front-end widgets.

Examples include transition effects, modal dialogs, dropdowns, scrollspy, tabs, tooltips, alerts, popovers, buttons, collapse, carousels, and affixes.