NPS: Client vs. NAS

Rearden

I'm hoping someone can help shed some light on this one. I'm working on studying for 70-411 and am a little lost on the difference between these two types of configurations in RADIUS scenarios.

From this technet link, https://technet.microsoft.com/en-us/library/cc731220%28v=ws.10%29.aspx I see the following descriptions:

Client IPv4 Address: Specifies the Internet Protocol (IP) version 4 address of the RADIUS client that forwarded the connection request to the NPS server.

NAS IPv4 Address: Allows you to specify the IPv4 address of the network access server that sent the connection request to NPS. If you specify a NAS IPv4 address and NPS receives a connection request from a NAS with a different IPv4 address, the conditions of the policy are not met.

They seem exceedingly similar and I'm having trouble wrapping my head around which is which.

Zartanasaurus

IIRC:
The NAS IPv4 address is something that might be configurable on the client if the vendor allows it.
The Client IPv4 address is based on the source address in the IP header.

Generally, they would be the same thing and using one vs the other in a policy won't matter.