All categories are marked with yellow checkmarks if you activate only the main slider of the column (at the top). This means that the right is granted for all categories that exist at that time. Also all categories created afterwards will receive this right automatically.
This saves you the work of having to check all categories individually, as well as the right to add new categories in the future.
If you don't want the right to apply to all existing categories, activate the main slider (all categories will be marked yellow) and then manually check the categories to which the right should apply.
These checkmarks will now turn blue and the yellow checkmarks will disappear (right removed again) for those categories that were not explicitly checked manually.
If a new subcategory is created in a category marked with a blue check mark in the future, this subcategory will automatically "inherit" the right assigned by the blue check mark for its main category.