What is my ip adress?

Your IP at your machine is a Private IP Address. The Gateway or Router/Modem is the machine that is "seen" by the ISP DNS server. The duty of the gateway is to let the DNS server at the ISP know its up and requests a Public IP Address then using NAT(Network Address Translation) it gives your computer its Private IP Address and all communication is set to run. All private numbers will be the 192.168.xxx.xxx by default and the router will use these to give to the machines in the Private LAN by DHCP and also DNS. The router has an input port(from Internet) this is the Public Address being used. The LAN ports for your home machines will use the Private Addresses and the router will give them out as needed. example: router public port is given 64.64.64.64 by you Internet Service Provider (ISP) the router itself will by default give itself a Private Address of 192.168.0.1 so the Private computers at home know to go to 192.168.0.1 their gateway to get information when needed. So now they just go to the routers private 192.168.0.1 to get their private IP numbers by default would be between 192.168.0.2 up to 192.168.0.255 Now because the Internet runs on Public IP's even if you had 30 computers at home using Private Numbers the router will still convert all those private numbers to the single Public number of 64.64.64.64 via NAT.

The 192.169 series is ONLY for private networks, it is not allowed on the Internet. And it can not cross any network boundary from one subnet to another. There are other such groups. Your machine can NOT talk to the internet. It has to talk to a router with an IP address in the same subnet. The router must also have an external address, this needs to be within the public group of addresses allowed on the Internet. If you use the site http://whatismyip.com it will tell you your external address, from your router. ALL machines in your network would show the same address. It is dynamic, and can change at intervals. If you open a command window (Start/Search and type cmd and enter) and type ipconfig and enter, it will show the IP address of the machine, AND the default gateway, which is the internal address of the router. If you want to learn more about addressing, the best descriptions I ever saw are in the Networking for Dummies book. Very detailed and picks up on all the things most other books miss.