When you click the "Required Settings" button in the Control Panel, you will see the popup window below where you need to submit some required and optional information. Required information includes Address, Tel, Currency Symbol and Rounding Adjustment for cash payment. If there is sale tax and a membership system for your customers, complete the respective fields on the Optional Settings tab. 

On this Settings popup, you can disable for the current Terminal - a cashier's terminal for example - all the command buttons on the Main window to various windows except the POS window.  You can also disable discount functions on POS window.

There are other numerous settings that can be made here.  Suffice to say that all these will be done only once during the initial setup of the system.

Click Submit button to save the settings.