Modals are streamlined, but flexible dialog prompts powered by JavaScript. They support a number of use cases from user notification to completely custom content and feature a handful of helpful subcomponents, sizes, and more. You can read full bootstrap documentation about Modals by clicking here

Modals have two optional sizes, available via modifier classes to be placed on a .modal-dialog. These sizes kick in at certain breakpoints to avoid horizontal scrollbars on narrower viewports.