What is the MACi address

The MAC address is a unique value associated with a network adapter. MAC addresses are also known as hardware addresses or physical addresses. It uniquely identifies an adapter on a LAN.
MAC addresses are 12-digit hexadecimal numbers (48 bits in length). By convention, MAC addresses are usually written in one of the following two formats:
MM:MM:MM:SS:SS:SS
MM-MM-MM-SS-SS-SS
The first half of a MAC address contains the ID number of the adapter manufacturer. These IDs are regulated by an Internet standards body.
The second half of a MAC address represents the serial number assigned to the adapter by the manufacturer. In the example, 00:A0:C9:14:C8:29 The prefix 00A0C9 indicates the manufacturer is Intel Corporation.