Server updates LUAs WHILE RUNNING?

Once on a server a update was done,WHILE THE SERVER WAS RUNNING…
All the lua’s were refreshed,the server did not shutdown and start up again,it just “Froze” and came back on with all the lua’s
again,yet things were obviously different.
How is this done?
And is this possible?

they changed a file and let the game auto refresh with the clients

obviously?

WTF it’s the poll for?
Also, in gmod when someone edits a lua file the server knows it and it refreshes that lua file or almost every lua file. Depending on the amount of lua files or the content in the lua file it can take a while to reload or just instantly. That explains that freeze you had

It’s called autorefresh