But it was clear to me that the distinction was not obvious to those on the call. To be clear, however, the presenter did say toward the end that this was all new and that she could use some help pinning down the definitions. So I decided to do just that; here are the differences.
Categories are taxonomy-based, meaning they are hierarchical. In other words, you can create a food category and then create a pasta category which lives beneath it. The pasta category can then have children as well, and so on. At least one category is required per post.
Categories should be added rather conservatively. Create as many categories as you need, but keep in mind that they’re used to find content, so avoid creating too many.
Tags are folksonomy-based, meaning they don’t have a hierarchy. They’re used to provide additional detail regarding the content of a post, but without cluttering the assigned categories.
Tags are designed to be used more loosely and informally than categories, and allow readers to pivot to related content from a given post. See the example from WordPress’s documentation on the topic:
My preference within my blogging platform (WordPress) is to use categories and not tags. To me there is simply too much overlap and not enough benefit to using both. I’d love to hear if someone disagrees, though. ::