A lot of people have this notion that routing involves some form of device that takes your data from your internal network and routes it out on to the internet. In part, this is correct, but for me, it is too specific a description and can be slightly misleading. A better definition would be that routing takes data from a network and forwards it through one or more networks to reach a destination network. These networks could be private to private, private to public, private to public to private, and any combination of any number of networks to get to the final destination.
In this subsection, I will briefly describe routing devices, and then talk about the common routing protocols available to us.