Networks Essential:

A network is a combination of hardware and software that sends data from one location to another location. The layers of the network are higher layer, middle layer and lower layer. These layers are present in both sender section as well as receiver section. Each layer at the sending side uses the services of the layer immediately. The open system interconnection (OSI) model is the ultimate standard for data communication. The international standard organization (ISO) is a multinational body decided to worldwide agreement on international standards. The OSI model was first introduced in the late 1970s. The purpose of the OSI model is to show how to facilitate communication between different systems without requiring changes to the logic of the underlying hardware and software. It consists of seven separate but related layers. The seven layers of OSI model are physical layer, data link layer, network layer, transport layer, session layer, presentation layer and application layer. The TCP/IP protocol suite was developed prior to the OSI model. The original TCP/IP protocol suite has four layers. They are host to network layer, internet layer, transport layer and application layer. They are four types of addresses used in an internet employing. They are physical addresses, logical addresses, port addresses and specific addresses. These are the general idea about the layers of a network and its function.