VMware Workstation 5.5Features | Documentation | Knowledge Base | Discussion Forums
The NAT (network address translation) device allows you to connect your virtual machines to an external network when you have only one IP network address on the physical network, and that address is used by the host computer. You can, for example, use NAT to connect your virtual machines to the Internet through a dial-up connection on the host computer, through the host computer's Ethernet adapter, or through a wireless Ethernet adapter. NAT is also useful when you need to connect to a non-Ethernet network, such as Token Ring or ATM.
The NAT device is set up automatically when you install VMware Workstation. (On a Linux host, you must choose to make NAT available to your virtual machines.)