What is the first building block of the OSI Reference Model?
For our purposes, the terms we use to describe how a network functions will be linked to the OSI reference model. Just as a house must first have a foundation before it can be built, so, too, must a network have a foundation upon which to build. In the OSI model, this foundation is called the Physical layer. The function layer is the transmission of data. Typically such transmission is accomplished through the use of such things as wires, connectors, and voltages. How is information stored in computers? Information in computers is stored using the binary number system, in which the only possible symbols, or binary digits, or “bit”, are 1 and 0. These bits – many of which are called data – are used to represent information, like text, pictures, and sounds. In the physical layer, a 1 bit is often represented by the presence of voltage (electrical pressure) on a copper conducting cable or light in an optical fiber. To help you picture these bits, imagine measuring the voltage at one point
