Once downloaded, unzip the compressed folder and you’ll see something like this:
This is the most basic form of Bootstrap: compiled files for quick drop-in usage in nearly any web project. We provide compiled CSS and JS (bootstrap.*), as well as compiled and minified CSS and JS (bootstrap.min.*). Source maps (bootstrap.*.map) are available for use with certain browsers’ developer tools. Bundled JS files (bootstrap.bundle.js and minified bootstrap.bundle.min.js) include Popper.
Bootstrap includes a handful of options for including some or all of our compiled CSS.