All pages and categories have at least one parent category that they belong to, but can have several at once. The only exception to this rule is the Dungeon Defenders 2 Category, as all content in the wiki must relate to this category in some way. When listing the categories for a page or category, list all the categories that relate to the single idea of that page specifically (not every single page needs the DD2 Category, only the most major and general of ideas should get it). For example, a Squire Ability should be listed under both of those categories, but does not need the Heroes Category because it is not an idea that is directly related to heroes in general, nor does it need Stats even though Abilities itself relates to Stats (because that specific ability is not a type of stat).
A category page is mostly there to list all ideas related to that category, in a very bland list format. This occurs automatically by the wiki, so it needs very little more for content. Most Category Pages should only have in their content the Categorize Template and then any Category that is parent of that one. Additionally, an article should explain that category, having the exact same name as the category, as well as having the same parent categories (in addition to itself as one of its categories). The Dungeon Defenders 2 Category however should never have a content page made for it, being the only category with no actual content, nor should it have an article made about it (The entire wiki as a whole does this). Some system-based categories won't have an article named after it either, and will always have either a system-based category parent, or have DD2 itself as it's parent (such as most articles in the project namespace, or every namespace category).