Physical Layer

Physical layer is the lowest layer in the OSI model of computer network. Physical layer regulations: provide mechanical, electronic, functional and normative characteristics for the creation, maintenance and removal of physical links required for data transmission. Simply put, the physical layer ensures that the original data can be transmitted on various physical media. LAN and WAN belong to layer 1 and 2. The physical layer is the first layer of OSI. Although it is at the bottom, it is the foundation of the whole open system. The physical layer provides transmission media and interconnection equipment for data communication between devices, and provides a reliable environment for data transmission. If you want to remember this first layer with as few words as possible, it is "signal and medium".