Web servers can host multiple websites with different domain names; to achieve this, they use virtual hosts. The web server software checks the hostname being requested from the HTTP headers and matches that against its virtual hosts (virtual hosts are just text-based configuration files). If it finds a match, the correct website will be provided. If no match is found, the default website will be provided instead. Virtual Hosts can have their root directory mapped to different locations on the hard drive. For example, one{.}com being mapped to /var/www/website_one, and two{.}com being mapped to /var/www/website_two There's no limit to the number of different websites you can host on a web server.