A Media Access Control (MAC) address is a unique identifier assigned to a network interface controller (NIC) for use as a network address in communications within a network segment. This means that every device connected to a network has a MAC address, including your router. The MAC address of your router is typically found on a label on the bottom or back of the device.
The MAC address is important because it allows devices on a network to identify each other. When a device sends data to another device, it includes its own MAC address in the header of the data packet. The receiving device then uses this MAC address to determine which device sent the data. This information is essential for ensuring that data is delivered to the correct device.