In the simplified OSI layering, which layer is described as the Host Layer, describing what's happening at the end device?

• A. Media Layer
• B. Host Layer
• C. Network Layer
• D. Data Link Layer

Answer: (B)

Understanding how the simplified OSI model maps end-user activity to a layer shows why the Host Layer is the right description. The Host Layer represents what’s happening on the end device—the applications, operating system, and host-based processes that originate, manage, and terminate data. It captures the perspective of the device itself, not the transmission path or the linking/switching between networks. The other layers describe the actual movement and framing of data over the network: the Media Layer covers the physical medium and signaling, the Data Link Layer handles framing on a link, and the Network Layer deals with routing between networks. So describing end-device activity aligns with the Host Layer, making it the best fit.