the `www` in changing permissions command

I’m following this tutorial to setup wordpress with nginx https://www.digitalocean.com/community/articles/how-to-install-wordpress-with-nginx-on-ubuntu-12-04. At one point it asks us to create and cd into a directory /var/www/

cd /var/www/

It subsequently tells us to change the permissions for that directory with this command

sudo chown www-data:www-data * -R sudo usermod -a -G www-data username

My question is this, is there a relationship between the www of the /var/www/ and the www of the www-data:www-data. For example, if I didn’t create the directory /var/www/ but instead created /var/foo/ directory, would the command for changing permissions look like this

sudo chown foo-data:foo-data * -R

or will the command always be

sudo chown www-data:www-data * -R

regardless of what I name the directory?