In the httpd.conf file look for the directive
# Virtual hosts
# Include conf/extra/httpd-vhosts.conf
This is the directive that informs Apache to read the contents of the httpd-vhosts.conf file at start up.
httpd-vhosts.conf is the file in which you can bind your website URL to a folder on your hard disk.
Unless appropriate entries are made in the httpd-vhosts.conf file Apache has no way of knowing where your Virtual Domain exists on your hard disk.
Please take a look at our Tutorial:
www.opensourcevarsity.com/apachebasics/l4creatingvirtualdomain
If you need help after studying the tutorial don't hesitate to post here.