As small as a pocket MP3 player, all the way to system on a chip, network switch, router, car computer, mobile phone, smart TV, robot, medical systems, ATM machine, laptop, AL/ML servers, etc. As far as you can think of, there are a lot of systems(or you can call them servers) running related to our daily life.
CPU, memory, and power are essential components for all systems to be operational. Of course, you can add on storage(SD card, HDD, SSD or NVMe), Ethernet, Wi-Fi, display, input/output or other peripherals depends on your need.
Will be updating more on server systems later. Stay tune.