A datalink represents a link object in the second layer (L2) of the Open Systems Interconnection (OSI) model. The physical link is directly associated with a device and possesses a device name. The device name contains the driver name and the device instance number. The instance number can have a value from zero to n, depending on how many NICs use that driver on the system.
The device instance name continues to depend on the system's underlying hardware. However, the hardware and software layers are separated, which means that the datalinks configured on top of these devices are no longer similarly bound. Thus, datalinks can be assigned names other than the device names on which they are configured.
By default, datalinks are assigned generic names that use the net# naming convention, where # is the device instance number. The instance number increments for each device on the system, for example, net0, net1, net2, and so on. For a more detailed overview, see About Datalink Configuration.