Virtual Hosts are used in Apache to allow a single web server to serve numerous websites.  Basically www.FailedNormal.com point to /var/www/FailedNormal, and www.EliTheComputerGuy.com points to /var/www/EliTheComputerGuy.

Other HTTP servers such as NGINXor IIS use the concept of Virtual Hosts, but may use a different name.

It is important to remember that websites all use the same resource pool (CPU/RAM/IOPS) so a single website can use. all the resources of a server and cause other websites to be very slow.