A virtual network adapter is a program (instead of a physical network adapter) that allows a computer to connect to a network. A virtual network adapter can also be used to connect all the computers on a local area network (LAN) to a larger network such as the Internet or a collection of LANs.
Microsoft's Mesh Connectivity Layer (MCL) technology is an example of the application of a virtual network adapter. In MCL, computers spread out over a community or other local geographic region are connected into a wireless mesh network using WiFi or WiMax. The wireless mesh network can be connected to the Internet through a single computer using a virtual network adapter and a leased T-1 line or broadband satellite connection, allowing all the network users high-speed Internet access. A virtual network adapter can also be used with a virtual private network (VPN), which is a network that uses a public telecommunication infrastructure, such as the Internet, to provide remote offices or individual users with secure access to their organization's network.