The Organisation details contain the basic details that you have entered at initial setup. - You can adjust these here any time. Supplying the organisation homepage is optional. - Provided that you entered your URL, every CCalendar user however, has the possibility to access your organisation homepage quickly with a link from the user menu. Hence, it is recommended.

With "Display German public holidays" you can turn the insertion of German public holidays in your individual organisation calendar on or off. This setting applies organisationwide for every user.
Confirm the input / change each with the button "Change data".