Posted on /sqg/, got no answer. Trying here:
So how does a VPN work? Like wireguard or something self-hosted like that? I understand what it does, but I don't understand how it does it.
>you're out and about
>connect to a certain address, on a certain port
>VPN picks up your connection
>now you're on your home LAN
>but you can still access the internet
So the connection comes in via the VPN, then goes out via your router to the wide web? Or does it only use the VPN to access stuff on your LAN and bypasses it when going out to the web? What's the deal with ports? If I can access the VPN from the net, why is it safer than opening your server to the internet without the VPN?

What steps should one take to secure & sanitize their computer before their girlfriend visits? She's somewhat tech-savvy.