Whats the difference between an adapter and a network interface?

Question

Having a hard time understanding the MSDN documentation on the IP Helper Functions. Whats the difference between an adapter and a network interface?

Answer 1

An "Adapter" is a piece of hardware.

A "network interface" is a software construct.

Usually, there is one network interface per adapter.

But there may be network interfaces which are not from an adapter.

And there may be multiple interfaces per adapter.

Answer 2

The MSDN docs are quite large. Here is a quote from the Managing Interfaces section that might help clear things up:

There is a one-to-one correspondence between the interfaces and adapters on a given computer. An interface is an IP-level abstraction, whereas an adapter is a datalink-level abstraction.

Answer 3

actually the fundamental concept is based on OSI model, so:

◾	an abstraction of	check it by	explanation
NIC (stands for Network Interface Controller) or (network card)	layer-1(Physical)	literally you should open the hardware of your machine and see that!	so that is a physical "interface" between "your machine" and "network" • common examples are: 1- ethernet network card 2- wireless network card
NA (network adapter)	layer-2(DataLink)	• Get-NetAdapter | Format-List name • devmgmt.msc->under net adapters	• a nic appears on your windows machine os as an "adapter" • be careful that you can also have some "virtual adapters" • common examples are: 1- Ethernet adapters 2- Token ring adapters 3- Fiber optic adapters
NI (network interface)	layer-3(Network)	or Get-NetAdapter | select InterfaceName, InterfaceDescription • ipconfig /all	until NA-Level, you couldn't utilize things like ip, routing, ..., using a network interface (or by installing a proper interface driver) now you can do so examples like: Loopback interface, Wireless interface, Ethernet interface

note-1: a network adapter's name maybe listed with it's interface name or description on different places like under "net adapters in devmgmt.msc"

note-2: in many occasions words "adapters" and "interfaces" may use interchangeably