Why IP address is logical and MAC address is physical?

A MAC (Media Access Control) address is physical because it physically identifies the NIC (Network Interface Card). When two NIC's talk to each other, they address each other by MAC address. In order for this to work, the NIC's have to be connected to the same physical network. If the two NIC's are on different networks, they must use an intermediary, such as a router or gateway, to proxy the message between networks.

An IP (internet Protocol) address, on the other hand, is logical because it sits at a higher level in the protocol stack. This is similar to the relationship between NetBiOS, NetBeui, IPX/SPX, etc.

• each of those protocols has an address, but they all ride on top

of the MAC layer.

There is certainly a relationship, a one-to-one relationship, between an IP address and a MAC address. This relationship is established by the ARP (Address Resolution Protocol) which runs alongside the MAC layer, or sort of in between the MAC layer and the IP layer.