Categories in Historian™ pertain to higher-level sections of your vault. It will automatically include Family, Events, and Friends, but you can right click on “My Categories” to see the option to create new ones if you wish. You can also create subcategories to organize your photos further. You can then tag your photos to go under these categories.
Ex: You may have the Events category, and then under this Vacations, Birthdays, Anniversaries, and so on.