I had a question in this article and i did not have the answer i want but i managed to do this:
in etc/apache2/sites-avaiable/000-default.conf i changed the DocumentRoot from /var/www/html to var/www
now localhost through the browser opens www i can see the html folder and the test site folder i want, now i can act for every folder as a separate site as i do in windows so the question is what is the difference between what i have done and the ten steps way that every body trying to explain to add more sites to apache and what is the benefits of these both ways?