Shared Hosting (or Shared Web Hosting) is a term in the Internet Hosting industry which refers to a number or Virtual Hosting accounts and websites hosted on one physical or virtual instance (server). Each virtual account has its own partition on the server in order to be separated from others. All those hosting accounts share the resources (processor, memory, bandwidth, software) of the underlying server. It can host thousands of websites.
Shared Hosting services is either name-based or IP-based. In IP-based virtual hosting each Shared account uses a dedicated IP address. The host server is configured with multiple physical network interfaces, or virtual network interfaces on the same physical interface. In name-based virtual hosting all Shared accounts on the server share a single IP address. In name-based hosting Web browsers request a resource from the web server of the host server using HTTP/1.1 which includes a certain hostname as part of the request. The host server uses this information to determine which web site to show the visitor.
Please note that term “Virtual Hosting” has nothing to do with “Virtual Private Server Hosting” (VPS, VPS Hosting, Virtual Servers ).