Internet is globally intranet is within the organization, extranet is also a part of intranet which is shared by companies with their clients because of business purposes.

There are 3 types of routing protocols> 1. Distance vector 2. RIP 3.IGRP

On the command prompt just type ipconfig/all and you will find the subnet mask and gateway address. Subnet mask is used for the network types and gateway is used for the internet connections.