Paths on a Mac?

How does OSX identify an external drive in terms of paths? What I mean is, on a PC a path to a file on an external drive might be something like:

Dfolder\filename.txt

or it could be via a UNC path like \\computer\folder\filename.txt

But how does OSX do it? I mean how does OSX identify one external drive from any other?

by it's mount point.. just like any other unix/unix-like OS.

Open terminal, type mount

attach your device and type mount again

you'll see the change.