Pos Touch Screen Terminals What Hardware Do I Need To Operate Retail Store - POS, PC And Server?

What hardware do I need to operate retail store - POS, PC and Server? - pos touch screen terminals

I did research on the hardware needed to run my store. That's what I want:

POS System
Customer Kiosk for Web browsing (presumably touchscreen, the software content filtering run)
Back Office PC

Question: I think I need to save a server for all customers, inventory, sales, etc., exchange of data and information from / to the point of sale. But I have to buy a server and a PC? Where can I get a server and use it as my PC back-office, too?