Enter the MAC address of an unknown device to find out who made it. The lookup reads the IEEE OUI registry and returns the registered company name, its office address and region, so you can tell a phone from a printer from a network card at a glance.
To reach the internet over Wi-Fi or Ethernet, your device needs a network adapter. At the factory every adapter is given a unique number — the MAC address (Media Access Control address). Because each packet has to arrive at exactly one card, the network uses this address to reach your hardware.
The Ethernet port is usually built into the motherboard. An RJ45 network cable plugged into the router on one end and into the computer on the other carries the traffic, and the Ethernet card has a MAC address burned in at the factory as well.
Think of a MAC address as the number on a house: your IP address can change every time you reconnect, but the MAC address stays with the hardware. A router reads it to label each frame, and the switch delivers that frame to the right port.
The article below shows how to find the MAC address of a device on Android, iPhone, Windows, macOS and Linux. How to Find a MAC Address