The rooms page is the main part of the GUI. Here you can organize the Home Items in Rooms. You see the main state of each Item and can access the actions of them, for example the on, off or toggle actions on a lamp. From this page you can also add new Items (or rooms) via the add-links.
By clicking on the name of an Item in the Rooms page, you enter the edit page of the selected Item. Here you can configure the Item, call all of its actions, rename it, move it to another room or delete it.