The Open Systems Interconnection (OSI) model is one of the many useful tools we can use to stop cybersecurity threats. This long-standing standard separates a network into seven layers, offering suggestions for protecting each of them. In this blog series, we’ll examine the layers one by one to understand this model. Each piece follows the same structure: what makes up the layer and what sort of threats you should be on the lookout for within that layer. The physical layer covers transporting all those zeroes and ones to wherever they need to go.”]
Source: https://securityintelligence.com/articles/osi-model-physical-layer/