Choosing sub-categories of a category to be observed or ignored

1. What is a purpose of a sub categories?
2. What is sub category in category?
3. What is the relationship between category and subcategory?
4. How do I make a subcategory dependent on a category in Servicenow?

What is a purpose of a sub categories?

The main purpose of displaying sub-sub-categories is to allow the user to make a more informed decision about which category scope to pursue. That the user is able to bypass an intermediate category page or two on their way is a nice bonus.

What is sub category in category?

plural subcategories. : a category that is a subdivision of a larger category : a secondary category. grouping the books into the appropriate categories and subcategories. A new subcategory of vodkas, which provide a contrast to the "tasteless" aspect of this spirit, are the flavored vodkas …

What is the relationship between category and subcategory?

A category can have one or more subcategories. If a category has subcategories, it is the parent category of those subcategories.

How do I make a subcategory dependent on a category in Servicenow?

In short your sub-subcategory depends on both category as well as your subcategory. If you want a choice to be displayed in the subcategory for two values in the category then create two choice records in subcategory for each value in category. Similarly with sub-subcategory field.