How bootstrap work correctly in laravel 5?

I am first to learn laravel 5.2 about one week. and I try to learn larevel from youtube and document laravel .but I wonder They teach and just copy templat bootstrap without download bootstrap file to put into folder public it works, but when I try to follow theme it not work for me ,but when I download bootstrap file and put into public folder and call it work for. My problam I want to know how bootstrap work correctly in laravel .

via Chebli Mohamed