Machine is generally names of your system or PC on which you have installed Software. Suppose you have five counter at each counter your PC installed with this software is kept obviously you will assign some individual name for this. So this Machine option helps you to add and delete your PC with network.
To Add Machine:
Though as you install this software names of that PC will automatically be catched into its network yet you can add or modify the names of machine by clicking Tools>Machine option. as you click on this a window will open. Below of this window you get an option of Add just click on it and write name of machine, display name and room no and then save.
To Delete Machine:
When you think to delete the names of machine just do double click on existing row and push Delete button.