Networking is any system of communicating . The word "Networking" has many other definitions and uses. We will focus on computer networking here, which involved exchange of information between computers. Computers act as nodes in the network. The largest networking system on earth is internet. The evolution of internet is long history. Some computer scientists first thought about sending information from one computer to another. This served as the prime idea behind developing the backbone of modern internet. Gradually the intercommunication between computers expanded before internet became possible. Internet is self sustained system. It does not have any central control. No one is now able to disrupt the process. It is expanding faster and faster by itself. That does not mean it is self conscious and intelligent. That is so called artificial intelligent and it can be threatening to human kind. There are protocols and rules that make internet possible. Every computer and the sub network have to maintain these protocols. There are several layers with predefined functions, which facilitate the inter-communication. In the hierarchy of the layers, some are below other layer making them dependable on the layers above it. TCP/IP is the most common protocol suites which tells a computer how to connect to another computer through their IP(internet protocol) address. In doing so, it also establishes connection between different sub networks that are parts of whole internet.n Each computer has unique IP address which serves as the identity for that computer. Although two computer can have same public IP but they can never have same private IP. Internet layer(TCP/IP) is the layer which is responsible for end to end communication. Data link layer facilitates the exchange of information between computers. Computer files or data are not directly transmitted from one computer to another. Each piece of data is divided into smaller chunks and they are routed differently to be assembled again before coming to destination. This is what data link layer does and assign IP address to each data packet or chunk. The data packets are turned into frames for suitable transmission.