In this post we are going to focus on the following process: “destination IP field of packet is checked against information stored in router”. The place where routing information is stored is called a routing table. Routing table contains routing entries, that is list of destinations (often called: list of network prefixes or routes).
Routing is the crucial process in IP networks responsible for IP prefix propagation and keeping the whole network topology in order. Having billions of IP addresses divided into many different subnets, without routing there would be muddle that will prevent the whole Internet from working. So, routing is like the set of rules that allows localize particular IP network and IP addresses that belongs to that network.