network cards
Network cards (or adapters) allow computers to connect with a local or global network. Common network cards support either Wi-Fi or Ethernet capabilities via a wire and port, connecting it to the computer. Special cards for specific networks are also available, however, are not suited for most homes or businesses. Network cards also carry the added function of creating your own private or public network. This is important especially for businesses who do not want the extra costs of running their network through a separate network provider.
References: http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/hnw_network_adapters.mspx?mfr=true
http://compnetworking.about.com/od/hardwarenetworkgear/a/networkadapter.htm
http://www.intel.com/products/desktop/adapters/pro1000gt/pro1000gt-overview.htm
References: http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/hnw_network_adapters.mspx?mfr=true
http://compnetworking.about.com/od/hardwarenetworkgear/a/networkadapter.htm
http://www.intel.com/products/desktop/adapters/pro1000gt/pro1000gt-overview.htm