DEFAULTSORT
Categories are intended to group together pages on similar subjects. Categories are supported by a MediaWiki feature that enables pages to be added to automated listings. This helps readers to navigate, sort, find related articles and see how information is organised.
Categories are normally found at the bottom of an article page. Clicking the category name brings up a category page listing the articles (or other pages) that have been added to that particular category. There may also be a section listing the subcategories of that category. The subcategorization feature makes it possible to organize categories into tree-like structures to aid navigation.
Read more about DEFAULTSORT: Summary, Putting Pages in Categories, Category Pages, Sort Order, Hiding Categories, Categories and Templates, Categorizing Redirect Pages, Moving and Redirecting Category Pages, Searching For Articles in Categories, "Related Changes" With Categories, Listing All Categories, Displaying Category Trees and Page Counts, Retrieving Category Information, Category Intersection, Union, Etc.