NAS and Airport Extreme

Sorry for the rookie question.  Is a 1TB Western Digital My Book USB HD connected to a Airport Extreme the same thing as a NAS?  Or will it function like one?

Thanks for the help.

Yes, this setup will work just fine.

A guide for setting up a network share to stream media from your NAS drive can be found at the link below.

http://support.firecore.com/entries/259299-streaming-files-over-the-network

Thanks Max