Not long after WordPress.com began we started calling categories “tags” in some places, most notably our global tags system.
However while our interface made it easy to add categories on the fly, many people were vocal in telling us that categories and tags were not the same thing, and eventually we figured out they were right. (Forgive us, we can be slow sometimes.)
What’s the difference between categories and tags, you ask?
As best as I can explain it, categories are things you create ahead of time and only have a few of. Imagine them like sections of your site. The signs on aisles of grocery stores. Tags are one-off keywords attached to a post. You may add a tag to a post that you’ll never use ever again. Categories are meant to be permanent, tags are ephemeral.
Of course that’s just the accepted usage, you don’t have to change a thing and are welcome to continue using categories as you have since you started your blog.
Before WordPress.com just supported categories, even though we called them tags sometimes, but some people used them as tags, including ourselves.
We’ve added real tagging now.
Now, at long last, there are separate interfaces for categories and tags so you can use either or both as you see fit based on your personal tagging philosophy. Categories are where they’ve always been to the right of the text box, and you can add tags below the post as a comma-separated list.
This is just the first step, we have some pretty exciting tag-related things coming in the future, so stay tuned.