Intel. See here:
http://standards.ieee.org/regauth/oui/oui.txt
•What is the physical address (the MAC address) of the NIC (or network adapter) for this connection?
MAC address stored in NIC card
No two cards ever manufactured should share the same address. If two cards contained identical MAC addresses problems would be encountered with network communications.
NIC
MAC bit size is 16 digits. but MAC bit is 48 each.
Doesn't matter if your connected to a LAN or not. The MAC address is hard coded into the NIC and does not change unless software on the computer requires that it changes.
Mac address
Source MAC address
getmacGetmac
ipconfig
Destination MAC address
MAC address