What is Ethernet? (And why does everyone talk about it without explaining it)

Imagine you’re in a room full of people trying to talk: some shout, some whisper, some use walkie-talkies.
How can they understand each other without chaos?
They need one clear rule on how to communicate.
On the Internet, for home or office networks, that rule is called Ethernet.

What is a Network?

A network is a group of devices (computers, printers, phones…) connected together to exchange information.
There are different types:

• Local Area Network (LAN): small, like at home or in an office.
• Wide Area Network (WAN): huge, connecting cities and countries (the Internet is a WAN!).

What is the OSI Model?

Don’t worry:
The OSI model is just a map that explains how data travels between computers.
It has 7 levels (layers).
The second layer takes care of sending data across the same local network.
And that’s where 🥁 Ethernet comes in!

How Ethernet Works

Ethernet is the method devices use to send data packets across a local network.
Each packet includes:

• Sender (MAC address of the device sending the packet).
• Receiver (MAC address of the device receiving the packet).
• Packet type (for example: is it a web page? an email?).

A MAC address is like the license plate of your device: unique, looking like this 64:1C:B0:12:34:56.

A Quick Example:

• You’re sending a message from a Samsung device to an Apple device on your home Wi-Fi.
• Samsung writes inside the packet:
  “Hi, I’m Samsung, I want to talk to Apple, this is a web page”.
• Ethernet grabs the packet and delivers it directly to Apple.

Want to talk to everyone at once? There’s a special address meaning “everyone listen!” (called broadcast).

What Happens When You Leave Your Home Network?

As soon as your packet leaves your local network (for example, to reach the Internet), the Ethernet “coat” is removed and replaced with a new one for the next network.

What We Learned Today…

✅ What a network and the OSI model are.
✅ What Ethernet is and how it works.
✅ What MAC addresses are.
✅ Why packets need sender and receiver addresses.

Interactive Quiz 🎯