It doesn't really work any differently to v4. Most of your v4 knowledge still applies to v6's behavior. Subnetting and routing works no differently, and neither do the addresses themselves (other than being longer). It's passing packets around in exactly the same way v4 does.

There are a few differences, e.g. default routes, IPs and maybe DNS come from RAs rather than DHCP. You also won't be using NAT, but that removes complexity so it should make things easier to understand.