This is the address you are on the internet with right now, and everything a website can read from it.
An IP address is the number that makes your device reachable on the internet. Every site you open gets to see it, because without that address the server has no idea where to send its answer. Your provider hands it to you, and on most subscriptions it changes every now and then.
Two addresses above? Then your connection runs dual-stack. The short one with dots is IPv4, the long one with colons is IPv6. Many providers now switch IPv6 on by default, and your browser picks it the moment a site supports it.
Your router usually shows a completely different address. At home your whole household shares one public address, and behind it the router gives everyone a private address starting with 192.168 or 10. Mobile internet goes a step further: with CGNAT, hundreds of customers sometimes share the same public address.
Usually yes. The European Court of Justice counts even a dynamic IP address as personal data, because together with your provider's records it leads to one connection. Your provider may only hand over that link in exceptional cases.
Your router shows the address of your home network. Toward the outside world your whole household uses one public address, and that is the address we see.
With most providers it does. After you restart your modem or after maintenance you often get a different address. A fixed IP address is usually a paid option on a business plan.
Down to your city or region, and no further. Only your provider knows which connection belongs to which address, and it does not hand that out lightly.
Yes, websites then see the address of the VPN server instead of yours. Everything else your browser gives away stays visible.