What Is Ethernet?
Ethernet — the dominant wired networking technology — the standard for connecting devices with cables in LANs, defining how frames are formatted and transmitted over copper or fibre.
How it works
Ethernet defines the physical and data-link standards for wired networking: cable types, connectors, frame format and how devices share the medium. It has scaled from 10 Mbps to 10/40/100 Gbps while keeping the same frame structure. Switches connect Ethernet devices, forwarding frames by MAC address.
Why it matters
Ethernet is the foundation of virtually every wired LAN — when you study switching, VLANs and frames in CCNA, you're studying Ethernet. Its simplicity and scalability are why it beat every competing LAN technology. See frames and switches.
Frequently asked questions
What is Ethernet?
The dominant wired networking standard — it defines how devices connect with cables and how data frames are formatted and transmitted in a LAN.
What speeds does Ethernet support?
From the original 10 Mbps up through 100 Mbps, 1 Gbps, 10 Gbps and beyond (40/100 Gbps) — all using the same fundamental frame format.
What is the difference between Ethernet and Wi-Fi?
Ethernet is wired (cables); Wi-Fi is wireless (radio). Both can be part of the same LAN, with Wi-Fi typically bridging onto the wired Ethernet network.
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