In this paper, I review the role of OSI-Model. This paper examines the problem of cybersecurity threats that are implemented on networks . OSI-Model is a 7 layer architecture with each layer having specific functionality to perform. All these 7 layers work collaboratively to transmit the data from one person to another all around the world. networks as being structured in the seven layers of the ISO-OSI model, it makes sense that cybersecurity threats can happen at any layer. We can think of these layers as the "links" in our metaphorical chain. Moving outward from the user, data is entered into the network through software running on the Application layer. Through the Session, Transport, Network, and Data-Link layers and arriving at the other end, the Physical layer, the data travels back up the seven layers to arrive at its intended destination. Each layer has its own protocols and other communication standards that govern its efficient operation. Each instance of osi Model provides services that use an instance directly. To provide the service itself uses an instance of the next lower instance.