Categories and Tags

• 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 automobiles, your categories would likely include “Cars,” “Trucks,” “Motorcycles,” and “Scooters.” You can have subcategories as well; hence, under “Cars,” you might have “Sedans,” “Luxury,” “Sports,” and “Hybrids.” An author can assign a post to any number of categories.
• 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 “Cars,” and then be tagged with “Maroon,” “Maruthi,” and “i10.”
• As a general rule of thumb: categories organize content, while tags label content.
• Any WordPress theme should enable content publishers to use either method of organization, and should make allowances for both in the theme design.