Synology Networking 102: How a VPN (Tailscale) Works

A very surface level explanation of how you can use a Tailscale VPN to access your Synology NAS when you're not in the same network. There's much more to networking and this subject than I, a mere hobbyist, can explain. But hopefully this lifts some of the fog on how VPNs work.
If you're looking to use a VPN for internet protection while using wifi at the airport or coffee shop, look up using the Tailscale feature called "exit nodes".
I don't go into it here, but if you have devices on a guest network they'll be treated as though they're on a separate network. You might have to look up resources on guest network setups if you need that. I know a lot Synology users use it for security cameras, and I believe Synology has a guide that specifically covers using cameras on a guest network with Surveillance Station.