[Question]Use DocumentRoot or in virtual host files ??

I am a newb, so please forgive my question if it seems silly.

I've been setting up some sites and have been using DocumentRoot in my virtual host files. While getting some Apache2 education, I found that the use of "Require all granted" is a must.See this page for reference For instance:
<Directory /path/to/public/website/>
Require all granted
</Directory>

Sorry for my confusion, but am I to use both? Is it okay to indicate the site's root more than once? Also, stuff seems to work without the <Directory.... stuff.