How can add images from folders that arent holding the html

Answer 1

just copy the address of the image
and putt it after <img src=...................>

Answer 2

But your page will load faster if it's in the folder

Answer 3

if your folder is inside the same folder as index.html and inside that folders folder is your image it would be
<img src="/imagefolder/img.jpg" alt=""/>
if you need to go back to a folder from the one you are currently in it would be
<img src="../previousfolder/images/img.jpg" alt=""/>