Probably known to many here, but an example of a very legitimate and traditional "magic packet" would be Wake-on-LAN, where a (simpler, lower power) circuit can

Probably known to many here, but an example of a very legitimate and traditional "magic packet" would be Wake-on-LAN, where a (simpler, lower power) circuit can recognize network traffic which indicates the machine needs to fully power on. https://en.wikipedia.org/wiki/Wake-on-LAN#Magic_packet https://en.wikipedia.org/wiki/Wake-on-LAN#Magic_packet One use-case might be to wake up your home computer so that you can access it remotely, without leaving it running 24/7.