At the wery beginning we talk about the historical development of the network protocol, its meaning and emergence as well as the conditions and the division and upgrade in TCP/IP. The network layer is a layer that deals with the transfer of data from the transfer layer of pages, the establishment and disconnection. The transport layer takes care of the packages that travel between the two computers. The presentation layer has the function to search for a general solution, that is the work of the user independently. As for the application layer, such a layer of OSI models is closest to the user providing online services to the user applications. The physical layer is one of the lowest layers of the model that performs bit transfer. The data layer takes care of the data exchange between network devices. The session layer is about establishing a connection between end users. The Internet is a publicly available global data network that connects computers and computer networks. It is based on the division between two computers on network. The role of the user (client), where the user always begins to communicate with the user. The role of a server that performs a task at the user’s request. The computer network has the function of an intermediary and serves to connect servers and users. It was developed in two versions: the IPv4 protocol and IPv6 protocol. With the IPv4 protocol, routing takes place based on the IP address, while with the IPv6 protocol before the routing is used, the database for forwarding information, in order to request confirmation of the destination address.e provision of IP addresses. The classic addressing of the IP address is divided into five main classes (class A, B, C, D and E). as for the network mask, we say that it is a 32-bit binary number that says which bits of the address should be viewed as bits of the network address. As for the delivery of the datagram itself, it is defined in the way that datagrams, by the control of the network layer, are treated and transmitted within one network while being forwarded to the next router, when the datagram passes through multiple networks. For the routing phase, routing tables are created.