What is Ethernet? Everything You Need to Know About Wired Networks

Simon Hill

Before Wi-Fi became ubiquitous, Ethernet was the way to link devices together. By running Ethernet cables in a local area network (LAN) or wide area network (WAN), you could send traffic back and forth. Ethernet enables machines to recognize data meant for them and to send data to other devices. It is still widely used because sending data along cables is faster, more reliable, and more secure than sending it as radio waves, as Wi-Fi does.

If you want to get the best from your internet connection, Ethernet is still a great way to do it, and it's an obvious choice for any organization that prizes high speed, security, and reliability. Here's everything you need to know about Ethernet. You may also want to dip into our guides on How to Buy a Router, Best Wi-Fi Routers, and Best Mesh Systems.

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First created in 1973 by a group of Xerox Palo Alto Research Center (PARC) engineers, including Robert Metcalfe and David Boggs, Ethernet allowed people to connect multiple computers in a local area network (LAN). Ethernet provided a set of rules for sending data back and forth between specific machines rapidly. The name Ethernet was inspired by luminiferous ether.

To massively simplify the early history of Ethernet, Xerox relinquished its trademark on the Ethernet name, and the Institute of Electrical and Electronics Engineers (IEEE) formalized the 802.3 standard (otherwise known as Ethernet) in 1983. Other technologies existed, but Ethernet soon became the dominant standard because it was open, so networking equipment was available from multiple manufacturers. Ethernet was also easy to upgrade, with each version offering backward compatibility.

The first official Ethernet release supported speeds of up to 10 Mbps. Then 100 Mbps Fast Ethernet came along in 1995, and Gigabit Ethernet followed in 1999. By 2002, 10-Gigabit Ethernet was possible. Power over Ethernet, or PoE, which enabled devices to use a single cable for power and networking, landed in 2003. Work has continued to increase Ethernet capabilities since, reaching 40 Gbps in 2010, then 100 Gbps later the same year. Research continues, but 40 Gbps is the top speed available for use in the home today, and that's way more than most of us need.

Even if you have only ever used Wi-Fi, you are probably familiar with Ethernet plugs and cables. The cable that connects your modem to your Wi-Fi router or main mesh unit is likely an Ethernet cable with an RJ45 connector. Ethernet offers three main advantages over Wi-Fi: It is faster, more stable, and more secure. But it requires you to run cables between devices, and connected devices must have Ethernet ports. Wiring up a network can also be complex and costly.

Ultimately, the speed you get will always be limited by the lowest-rated component, whether that's the cable, port, or switch. Let's take a closer look at all three.

There are seven categories of Ethernet cable in use today, offering various maximum bandwidth and data rates.

Jeremy White

Jeremy White

WIRED Staff

Medea Giordano

At the basic level, cables have pairs of wires twisted together with a plastic covering (UTP, or Unshielded Twisted Pair), but some cables have metallic or foil shielding (STP or FTP, which stand for Shielded Twisted Pair or Foiled Twisted Pair). In addition to shielding guards against electromagnetic interference, it also makes cables thicker and less flexible. Whenever you buy an Ethernet cable, the manufacturer will specify its capabilities, but cables usually have basic specs printed on the plastic casing.

While they are generally quite hardy, there is always a risk that Ethernet cables can be damaged, especially if you plug and unplug them often. If you run cables around your house, be careful about tight bends and avoid high-traffic areas where they might get bumped or trampled. Thin or flat Ethernet cables may be tempting, but they often have less shielding and are less durable.

Jeremy White

Jeremy White

WIRED Staff

Medea Giordano

When an Ethernet cable is damaged, it doesn't necessarily stop working entirely. But it may be identified by connected devices as a lower category cable, which will limit its speed. I was surprised when this happened to me. A Cat 7 cable rated at 10 Gbps had been working fine for months, but it got damaged without me noticing, and the router I was testing limited my 1 Gbps connection to 100 Mbps. There is also a limit on how long an Ethernet cable can be before the signal strength drops, but that's usually not something you need to worry about when wiring your home.

Because of the hassle of running cables, especially if you hide them in walls, ceilings, or floors, it is best to future-proof and get a Cat 7 or Cat 8 cable. The price difference is minor anyway, and they are backward compatible. I use a 10-foot Amazon Basics Cat 7 Ethernet Cable ($11), which works perfectly for my Gigabit internet connection. Both the flat cables I have tried developed faults.

Many routers and mesh systems today have a limited number of Ethernet ports. Like cables, they have different ratings but are usually more straightforward. Gigabit ports are common: Several routers offer 2.5 Gbps ports, and a handful of routers support 10 Gbps. The maximum data rate tends to be printed on the port for routers. You may have to check the specs for other devices.

Whether you need more ports or want to route Ethernet cables around your home, you may need an Ethernet switch. Ethernet switches come in various sizes and enable you to run a single Ethernet cable from your router and multiple cables out to different rooms or devices. I am currently using this Netgear Five Port Gigabit Network Switch ($33), but you can get switches with more ports, like this unmanaged eight-port model from TP-Link ($25) that WIRED reviews editor Julian Chokkattu uses.

Switches are usually described as managed or unmanaged. Opt for managed if you like to tinker and want to configure and monitor settings, prioritize channels and traffic, and potentially get more security features. Unmanaged switches are just plug-and-play, but they are usually cheaper and will work fine for most homes.

Running Ethernet cables around your home can offer the speed, stability, and security advantages we mentioned, but how tough it is to do depends on the construction of your house and your willingness to drill holes. Wi-Fi is much easier, but the speeds you get with Wi-Fi will always be far lower than the actual speed your internet service provider supports. By using Ethernet cables, you get much closer to those maximum speeds.

Cables to every room would be too disruptive for most folks, but anyone with a mesh system that supports wired backhaul should consider running an Ethernet cable from their main router to their nodes or satellites to get the best performance from their system. Otherwise, the mesh will use one of the wireless bands to send traffic back and forth, which limits the bandwidth available for devices and results in slower Wi-Fi speeds for any devices connected to a node.

Jeremy White

Jeremy White

WIRED Staff

Medea Giordano

Even if you use wireless backhaul, if you have a spare Ethernet port on a node, it is often worth running an Ethernet cable from it to any device in the room. Smart TVs, game consoles, and computers usually have Ethernet ports, and running a cable always offers better speed and stability than Wi-Fi.

If you rent or simply don't want to start drilling holes to run cables, there are a couple of alternatives. The first is to use a long Ethernet cable and these adhesive cable clips to route the wire through your space without having to drill anything; it's what WIRED reviews editor Julian Chokkattu did in his rental. Here are a few other options:

Wi-Fi is still likely the best solution for most folks because it is so easy to connect devices. Wi-Fi 6, Wi-Fi 6E, and the fast-approaching Wi-Fi 7 have made very high-speed connections possible, offering more than enough bandwidth for typical tasks like streaming video or online gaming. If Wi-Fi works for you, stick with it, but it is more prone to interference and instability, so if you run into issues, you might consider Ethernet. After all, sometimes wired is better.