Continuing with the crowded room analogy, protocols provide the following four functions: One, they provide a common means to address someone so that it is clear who is speaking and to whom; Two, they provide a means control who may talk, when, or if at all; Three, they provide a means to limit how long someone is allowed to talk so that others conversations get a chance to be held; Finally, they provide a means to detect and manage a situation where two people begin talking at the same time (i.e. network traffic collision).The Internet Protocol (IP) component of the TCP/IP protocol provides the mechanism for addressing traffic. It provides a means of indicating where data originated and to where it ought to be routed. The Transfer Protocol (TCP) component of the TCP/IP protocol provides the mechanism that facilitates the actual routing of data from one IP address to another. It is responsible for breaking up data into the packets that are transferred across a network, providing the logical connection to the network, and a means to determine if all the packets of a transmission have reached their intended destination. It also facilitates the use of ports, permitting the division of traffic.
Conceptually, a network is nothing more than a shared location used by several entities to communication with one another. Like a crowded room where so many conversations are being held that no one can hear any of them, protocols are used to establish a degree of order.