Gougi

Greetings, i have an internet cafe with 12 pc's with limited internet bandwidth, their is a lot of steam games update and i cant update every single computer, and the backup/restore process takes a lot time and resources. so i was wondering if their is a way were we update one computer and send the update to the rest.(please dont say copy/paste) I've been reading and found something called steam cache, but i didn't understand what it is. thanks in advance for all ur help.