Don't be confused.
The 192.168.1.1 is the ip address of your router (and mine) and is the one your pc and wireless gadgets use to connect to it. Each gadget may have a different last number.
The public ip address is different. You can yours here:
http://whatismyipaddress.com/
This address is given by your internet provider and can change, especially if you turn your modem/router off.
This is the address that AnswerBank Ed can see when you post. He can block this ip address and stop you posting on AB.
This is true of every forum and website you visit.
If you use your pc for criminal activity the police can track you down through this ip address. Even though it changes the internet provider knows who was using that address at a particular time.
Every modem/router will be using a unique ip address at a time.
If your wifi is not secure, Joe Bloggs can log on to the internet using your router. You probably would not be aware of it. Could be your neighbour, someone in a car outside your house, that kid leaning on the lamp post with a smartphone in his hand. If Mr Bloggs commits a crime it will be tracked to your wifi network and you.