Categories and Tags: what’s the difference?
Posts are the primary content type of most WordPress sites, and are usually quite numerous. As a result,WordPress includes a few features to help publishers organize posts, making them easier for readers to find.
Categories are a hierarchical method of organizing the site’s posts. For instance, if you have a site that offers reviews on luxury sports cars, your categories could include “Ferraris,” “Aston Martins,” “Porsches,” and “Maseratis.” You can have subcategories as well; hence, under “Ferraris,” you might have “458 Italia,” “California,” “FF,” and “250 GTO.” An author can assign a post to any number
Tags are a way of attaching keywords to blog posts. Unlike categories, tags aren’t organized into any sort of hierarchy. Essentially, they allow you to be more granular in your classification of content. Using the previous example, a post could be filed under the category of “Ferraris,” and then be tagged with “Red,” “Grand tourer,” and “V8.”
As a general rule of thumb: categories organise content, while tags label content.