MAC Address

MAC Address is also known as the Physical Address.
This address is assigned to a NIC (Network Interface Card) during its manufacture by the manufacturing company  itself.

Its 48 bit address represented in Hexa decimal.
It cannot be changed by the user.
Its Unique.

To see your PCs MAC Address.

Start> Run> cmd
c:\> ipconfig  /all

To See Ip Address

C:\>ipconfig


Eg:  Let A1B2-C3D4-E5F6 be a MAC Address

Here single digit represents 4 bits. Total 12 digits. Hence 48 bit address.
First 24 bits is called as the OUI - Organisational Unique Identifier
OUI is to represent an organistion.
Its also called as Vendor Specific or Device ID or Vendor Assigned.
So with the 24 bits we can identify the manufacturer of the NIC.

The rest 24 bits will be unique for each OUI.