Plainly
look up a word, understand it — no rabbit hole
monitor
nounmeaning in plain English
A person who watches over others to keep them safe or make sure rules are followed.
Picture a night-shift guard with a screen - he's the monitor, watching everything to keep you safe.
for example
The night monitors walk around the sleeping kids to make sure everyone is okay until morning.
Imagine you’re at a sleepover and someone has to stay awake to watch the others. That person is a monitor — they’re there to keep an eye on things so nothing goes wrong.