OSI 7 Layers

Open Systems Interconnection Reference Model, also known as the OSI model, is describe how information is transferred from one networking component to another networking component. It is a conceptual model. normally, real-world networks comply to the OSI model, although some differences exist between the OSI model theory and actual practice in real networks. Still, the OSI model offers an excellent way to understand and visualize how computers network to each other. OSI Reference Model separates the network communication process into seven simple layers. Network communication starts at the application layer of the OSI model (on the sending system) and works its way down through the layers to the physical layer. Each layer of the OSI model is responsible for aspecific function or task within the stages of network communication. And each layer is responsible for communicating with the layers immediately above it and below it. The first three layers are sometimes called the lower layers. And layers 4 through 7 are sometimes called the upper layers.