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.