To open any category in the web site or any informative unit or to activate any action, just click once on the respective link in the menus.

When browsing the web site – through categories and sub-categories, to return to one of the previous categories, use the navigation line, where the title of each category is a hyperlink and clicking on it will open the respective category:

Data input or confirmation of request in forms is done with screen buttons, e.g. Save or Add.
When entering data in the forms, you can navigate from one box to another by clicking there with the mouse, but it is much more easier to do the same by pressing the <Tab> key on your keyboard.