So when I use one of those ip address websites, its different from when I use command prompt and type ipconfig. This only applies to my ipv4 and not my ipv6.
127.0.0.1 is internal you your device - localhost..
command prompt - ip address from router : internal - likely 192.168.?.? or 10.?.?.?
websites - ip address given by ISP or VPN : External..
so which is my "real" ip address?
basically your cable modem (or dsl modem etc) will have an ip address assigned by your ISP provider and that is your 'real' IP address. But people might have 30 or more devices (tablets, phones, computers, thermostat, etc. etc.) and your ISP is not going to assign 30 to each customer they have since they have a limited amount of them.... So for networking you have a router, which then assigns 'internal' ip addresses on a private network for yourself, and routes all the traffic to the one IP from your provider.
So for example, if your ISP provides you a modem only, you can use one device. Then either you provide your own router or there is one built into the modem which gives you the internal network. The other device is a switch (or hub) where you can connect multiple devices to, but does not have a router (the router assigns your internal IP address, the switch just lets you get multiple on the same network). You usually have one modem, one router, and possible multiple switches. Devices on one subnet can't talk to devices on another subnet so if you have two routers (maybe one in a wifi router elsewhere) most will turn off the router part in the 2nd device so everything stays together.
Easy to see your internal network, all the IP's will start with 192.168.x.x Your real IP will have some IP address that does not start with 192.x.x.x Your real IP will be unique, but everyone has the same IP's internally to their private networks. It just lets you re-use the same ip ranges across the millions/billions of people with a private network instead of have everything truly unique.
go here to view your ip address