macaddress

2. A unique identifier burned into a network adapter by its manufacturer.

Every network card has its own macaddress that never changes.

3. A string of numbers and letters used to allow or block devices on a network.

The office router only lets in devices whose macaddress is on the approved list.

4. A label used by technicians to tell one piece of hardware apart from another.

Write down the macaddress on the sticker before you recycle the old laptop.