The OSI model

- [Instructor] The Open Systems Interconnection, … or OSI group, … has created a conceptual model … that helps us further understand … how computers talk to each other … and the level of responsibilities … that each layer of the model has. … This helps us simplify all of the things … that are going on from the cabling itself, … to the network card, … the driver software that runs on that card, … all the way up to the operating system on top of that. … The OSI model demonstrates the various functions … of a standard communications system. … It starts at the lowest level, the physical one, … and works up to the highest level, the application level. … Layer one of the OSI is the Physical Layer. … This is the ethernet card that has a cable plugged into it. … The electrical pulses over that cable … that represent bits of data that make it, … through a series of hops, to the other end. … It says nothing about the data, … just that it exists as a series of ones and zeros. … It's the physical layer, …