Which of the following describes Ethernet?

Ethernet is primarily defined as a method used to transmit packets on a network. It operates by using a protocol that governs how data packets are formatted, addressed, transmitted, and received across a wired local area network (LAN). This method allows devices within the same network segment to communicate with each other efficiently.

Ethernet technology has evolved to support varying speeds and types of cabling, from traditional coaxial cables to twisted pair wiring and fiber optics. It establishes rules and procedures for data transmission, including how to detect collisions when two devices attempt to send packets simultaneously, ensuring reliable communication.

In contrast, other choices like wireless transmission, secured data transfer protocols, and network routing methods describe different aspects of networking that do not specifically relate to the core function and definition of Ethernet as a wired communication standard. Thus, the focus on packet transmission precisely aligns with the fundamental role of Ethernet in network infrastructures.