Which layer of Ethernet is responsible for physical connections?

The Physical Layer is the first layer of the OSI (Open Systems Interconnection) model and is primarily responsible for the physical transmission of data over a network. This includes the wiring, cabling, connectors, and signaling mechanisms used to transmit raw bitstreams over a medium. The Physical Layer defines the hardware elements of a network, such as electrical signals, light signals, and radio waves, along with the physical aspects that enable them to function, including voltage levels, timing of voltage changes, and the physical characteristics of the transmission medium.

In the context of Ethernet, the Physical Layer encompasses standards related to cables like twisted pair and fiber optics, as well as the specifications for how bits are represented by electrical or optical signals. This layer ensures that the data is transmitted accurately between devices over the physical medium, making it essential for establishing and maintaining network connectivity.