Within the internet, information is not transmitted as a constant stream from host to host Rather a data is broken into small packages called packets Esch packet is marked with a sequence number, the address of the recipient and the address of the sender. In addition TCP inserts some error control information. The Packets are then sent over the network, where it is the job of  IP  to transport them to the remote host  At the other end, TCP receives the packet and checks for error. If an error has occurred, TCP can ask that particular packets to be resent because an image of the data is sent, the original data is not sent, Once all the packets are received correctly, TCP will use the sequence numbers to reconstruct the original message, In other words, the job of IP is to get the raw data is correct, thus TCP is the transmission protocol and IP is the network protocol.
Breaking the data into packets has several important benefits, First, it allows the Internet to use the same communication lines for many different users at the same time since the packets do not have to travel together, a communication line can carry all types of packets as they make their way from place to place As packets travel, they are sent from bost to host until they reach their ultimate destination. Special purpose computers called routers, choose the actual route. This means the Internet has a lot of flexibility
If a particular connection is disrupted, the computers controlling the flow of data can usually find as an Alternate route. In fact, it is possible that within a single data transfer, the various packets might follow Different routes to the same destination. This means that when a particular part of the network becomes Overloaded, packets can be routed over other less busy lines, Another advantage of using packets is that when a small transmission error occurs only a single packet will need to be resent rather than the entire message. This greatly increases the overall speed of the internet.
The internet is dependent on the existing infrastructure developed by telecommunication companies Internet service providers lease data circuits from the telephone networks and have dedicated computer at the endpoints or node, These rely on the distributed intelligence of networking equipment known a ‘routers’, thus bypassing the telephone company’s expensive switching computers while using their transmission lines All the content of internet is held by computers known as the “servers”. Which are owned by organizations and companies who want to distribute the information?
When a request is made to these servers for the information, they bundle the requested information in small packets, with the address as to where it is to be sent, and send them down to the nearest connection to the Internet. When they arrive at the Internet, the packets are read by the router, which is nothing more than a traffic cop and sent down in the same general direction as the address. A similar thing happens at the next junction on the Internet. This goes on until the packet is delivered to the right address. Where it is put together again with other packets, to make up the original information.
Network host handles the task of translating message transmitted over the Internet passes through at least three levels of protocol: The protocol used by the internet for getting messages from one machine to another is called internet protocol (IP) The internet protocol is a network protocol and its job is to manage the logistics of getting a message from the sending machine to the receiving  machine After the Internet protocol has done its work, the transmission Contol  protocol (TCP) and User Datagram Protocol (UDP). Finally, the application protocol that runs the network transmission into something a human being can recognize as the answer. 

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