Let us say we have two people in a room, they have to talk to each other. You can simply talk them. Now if you have more than 2 people, you need to refer to their names for clarity. If you have to talk to a friend but he lives in a different house than yours, now you need to a proper address to reach to him. But what if there lives multiple people, you will just share the message to a gatekeeper. The gatekeeper will forward the message to the right house. If the house is not under his radar, the gatekeeper will request the next gatekeeper until it finds the right house. Similarly, if you want a data within your house, you can ask directly. But if you want to get the data outside your house, you need to ask a gate keeper to get the data for you. This gate keeper is called a router. The router does not have the data itself but a server has. Once the server is identified, the server sends the data to the router and the router takes this data and send to the previous...