External IP address
An external IP address is the address assigned to you by your Internet Service Provider that is how the Internet and all other computers outside your local network see you.
In the above picture, there are three computers in the local network that have each been assigned their own internal IP address by the router. The ISP is connected to the router and gives the router an external IP address that allows it to communicate with the Internet. While on the Internet everyone sees your external IP address, but any information coming from the router is routed from the external IP address to the internal IP address.