By default start page is index. This means that this page will be shown first when you access your domain. Furthermore, index.php will always be shown before index.html, meaning that for example your PHP site is shown and not your Website Builder (HTML) site.
Step 1. Enable mod_rewrite on your Apache web server.
Step 2. Create .htaccess file in root directory.
Step 3.Update default page for your website home.html in .htaccess file
Step 4. Restart Apache Server
sudo service apache2 restart