What type of devices are categorized under the physical layer of networking?

The physical layer of networking, as defined by the OSI (Open Systems Interconnection) model, encompasses devices that are directly involved in the transmission and reception of raw bit streams over a physical medium. This layer deals with the hardware elements that facilitate the interaction between the network and the physical environment.

Devices that fall under this category include network interface cards (NICs), switches, routers, and cabling, all of which are critical for transferring data. These devices ensure that bits are transmitted across different media, be it copper cables, fiber optics, or wireless connections. They do not process the data or understand its content; their sole purpose is to ensure that signals are accurately transmitted from one point to another.

Other options, such as computers, application servers, and network management tools, operate at higher layers of the OSI model. Computers and servers are responsible for processing data and applications, while network management tools are designed for monitoring and controlling the network, focusing on the logical and management aspects rather than the physical transmission of bits.