Understanding CORS AJAX fetch problems

Trying to make an AJAX call and fetch data from your web server but you keep getting CORS issues? Keep getting Access-Control-Allow-Origin errors in the browser console?
This video explains how to resolve those problems by adding an Access-Control-Allow-Origin header through your Apache .htaccess file.
HTML/JS Code GIST: https://gist.github.com/prof3ssorSt3v3/1a77ea13d4c7a278061adf6f89bf1e51
.htaccess Code GIST: https://gist.github.com/prof3ssorSt3v3/6bff66af31611960107666ac7aba1d69
AJAX Fetch playlist: https://www.youtube.com/watch?v7EKebb4VUYQ&listPLyuRouwmQCjkWu63mHksI9EA4fN-vwGs7