I am try to configure virtual hosts, but the tutorial from DO doesn't works.

I use this tutorial from DO but, it doesn’t works: https://www.digitalocean.com/community/tutorials/how-to-set-up-apache-virtual-hosts-on-ubuntu-16-04

I see that the structure of virtual host file configuration (Eg: example.config) is different that the tutorial is showing.

<VirtualHost *:80> ServerAdmin webaster@domain DocumentRoot /var/www/html

    <Directory /var/www/html/>
        Options Indexes FollowSymLinks
        AllowOverride All
        Require all granted
    </Directory>

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

    <IfModule mod_dir.c>
        DirectoryIndex index.php index.pl index.cgi index.html index.xhtml index.htm
    </IfModule>

</VirtualHost>

What is the problem?