Today we'll discuss routing as it pertains to computer networking and not woodworking. We can talk about the woodworking angle another day if desired.
If you think of a computer as a house, then computer networks are like neighborhoods. If you want to visit your neighbor, you can just walk next door and knock. But let’s say you want to visit your cousin in a completely different neighborhood. Then it involves more than just walking down one street. You'll be presented with intersections where you'll need to choose directions. Network routing is a list of these directions or, more accurately, the street signs.
When you get to an intersection (router), you look up your destination on the street sign (routing table) and make the turn. Then when you get to the next intersection you repeat the process (check sign, make turn). You do this as many times as necessary until you get to the final street (destination network) where you walk up and knock on the door (destination computer).