One of my pet peeves is when someone writes about MAC computers. Mac is not an acronym. It’s short for Macintosh.* So why do so many people write MAC? My best guess is that these folks are familiar with PCs, so they apply the capitalization to Macs too.
MAC is a technical acronym that you might have seen before. It’s short for Media Access Control. Every network interface, such as Wi-Fi or Ethernet has a MAC address. MAC addresses aren’t an Apple thing per se. MACs are a networking thing. If you’d like to see your Mac’s MAC addresses, you can find them in a variety of places, including the Network System Preferences panel, the System Report, or the output of ifconfig on the command line.
*Apple hardly uses the name Macintosh anymore, with the notable exception of the drive in your Mac, named Macintosh HD. Recent Mac models don’t have hard drives, they have SSDs. So Apple could very well retire the Macintosh HD naming convention in a future macOS.