How to become a system administrator, some details?

Question

System administration

In my city, mainly system administrators are required, the system is generally as follows:
There is an electronic menu in the cafe, a person makes an order and he goes to the kitchen to the chef ... :)
Your task is to ensure that this order reaches the chef, as something through the server.
And here is the question of what you need to study and be able to do in order to work in this area. I myself was engaged only in front-end, almost half a year.
Thanks to :)

Answer 1

you need to know local networks, operating systems, 1s, have experience with posix systems and terminals, and the software they work with

Answer 2

They are NOT system administrators :-) They are programmers, web developers or whatever, but not system administrators.

Answer 3

You need to study the backend. :)
Tobish all the ins and outs of the process from pressing the menu button, to displaying on the screen at the cook "Hey, let's souffle."