a question about license

Created by: ghost

Hi, I have a question about license. So under the "License FAQs" on getbootstrap.com I saw the following information:

"It requires you to: Include the license and copyright notice in your works"

What does it mean? I don't understand exactly. Does it mean, I have to show up the "license and copyright notice" on my website pages? Or do not clean license and copyright notice in the top of bootstrap .js and .css files? Or another?