Thank you for the suggestion @omeratagun. As my aim in this tutorial is to help newbies get started with coding in Bootstrap as easily as possible, I have shown people how to include Bootstrap using CDN, which will allow them to code in Bootstrap without downloading it. Downloading bootstrap into the local folder could be another unnecssary step that could put newbies off using it. However, as you suggest,  I will make a separate video to show people how to download bootstrap later. Thank you.