web hosting can also be done privately by sharing the cost of running a server in a colocation centre; this is called cooperative hosting. Implementation Shared web hosting can be accomplished in two ways: name-based and Internet Protocol-based (IP-based), although some control panels allow a mix of name-based and IP-based on the one server. IP-based In IP-based virtual hosting, also called dedicated IP hosting, each virtual host has a different IP address. The web server is configured with multiple physical network interfaces or virtual network interfaces on the same physical interface. The web server software uses the IP address the client connects to in order to determine which website to show the user. Name-based In name-based virtual hosting, also called shared IP hosting, the virtual hosts serve multiple hostnames on a single machine with a single IP address. This is possible because when a web browser requests a resource from a web server using HTTP/1.1 it includes the requested hostname as part of the request. The server uses this information to determine which website to show the user. Understanding DNS and name servers DNS stands for "Domain Name System". The domain name system acts like a large telephone directory and in that it's the master database, which associates a domain name such as www.wikipedia.org with the appropriate IP number. Consider the IP number something similar to a phone number: When someone calls www.wikipedia.org, the ISP looks at the DNS server, and asks "how do I contact www.wikipedia.org?" The DNS server responds, for example, "it can be found at: 91.198.174.192.". As the Internet understands it, this can be considered the phone number for the server that houses the website. When the domain name is registered/purchased on a particular registrar's "name server", the DNS settings are kept on their server, and in most cases point the domain to the name server of the hosting provider. This name server is where the IP number (currently associated with the domain name) resides. See also Dedicated hosting service Virtual machine Virtual private server Web hosting service Web server References Internet hosting IT service management Telecommunication services Web hosting