What is ethernet?

Ethernet is a family of wired networking technologies that lets computers and other devices talk to each other over a cable. It defines the rules (protocols) for how data is packaged, sent, and received, and it uses a special type of cable called twisted‑pair (like the common RJ45 cable) or fiber optics.

Let's break it down

  • Cable: Usually a copper cable with an RJ45 connector, similar to a phone plug but a bit bigger.
  • Speed: Modern Ethernet can move data at 100 Mbps, 1 Gbps, 10 Gbps, or even faster.
  • Frames: Data is broken into small packets called frames, each with a header that tells where it’s going and a checksum to check for errors.
  • Switches: Small devices that connect many Ethernet cables together, directing traffic so each device gets the right data.
  • Standards: The IEEE 802.3 family defines the exact specifications (e.g., 802.3u for 100 Mbps Fast Ethernet, 802.3ab for 1 Gbps Gigabit Ethernet).

Why does it matter?

Ethernet provides a reliable, fast, and inexpensive way to connect devices in homes, offices, and data centers. Because it’s wired, it’s less prone to interference and security problems than wireless connections, making it ideal for tasks that need stable, high‑speed data transfer such as video streaming, online gaming, and large file transfers.

Where is it used?

  • Home networks (connecting routers, computers, smart TVs, game consoles)
  • Office LANs (linking workstations, printers, servers)
  • Data centers (connecting racks of servers and storage)
  • Industrial settings (controlling machines, sensors, and robotics)
  • Public places like schools, hospitals, and hotels for wired internet access

Good things about it

  • Speed: Can handle very high data rates, especially with newer standards.
  • Reliability: Wired connections are stable and less affected by walls or other wireless interference.
  • Security: Physical access is required to tap the network, making eavesdropping harder.
  • Cost‑effective: Cables and switches are relatively cheap compared to many wireless solutions.
  • Scalability: Easy to add more devices by plugging into a switch or adding more ports.

Not-so-good things

  • Physical limitation: Cables must run between devices, which can be messy or impractical in some spaces.
  • Installation effort: Running new cables through walls or ceilings can be time‑consuming and may require professional help.
  • Mobility: Devices are tied to a socket, so you can’t move them freely like with Wi‑Fi.
  • Port limits: Each switch has a finite number of ports; expanding beyond that needs additional hardware.
  • Obsolescence: Older Ethernet standards (e.g., 10 Mbps) become too slow for modern applications, requiring upgrades.