Category vs. Tag vs. Keyword

Previously on the CogitActive Saga:
By grouping posts together based on a select number of relationships, it makes it easier for readers to find information on a specific topic, as well as related content. By default, a standard post will have two taxonomy types: Categories and Tags.

Taxonomy, there and back again! Granted, they are essential to the WordPress platform, but why would I write another post about categories and tags, knowing that these were the topics of my two previous posts, respectively? The answer is that I believe it is worth expounding on the subject because, in many respects, they can make or break the blog experience. Besides, while I have covered each of them separately, I didn’t address the main differences between them and, more importantly, how to use them together.

“OK, but what about keywords then?”

You may know that keywords are important words (or phrases) that people are likely to search for if they were looking for the content you are publishing. Accordingly, you want to add keywords to your site to improve your SEO, right? However, the question is where and how to add them. Well, your targeted keywords must be scattered through your entire site’s content. In other words, there isn’t a dedicated place for listing them. Actually, that is not entirely true; there are (or were) such a place: the meta keywords element.

Often people mistake tags to be like meta keywords for your blogs. This is the main reason why they try to add as many tags as possible. Tags are NOT meta keywords for your blog.Syed Balkhi

Now that the scene is set, let me move forward with the following question: what are the differences between categories and tags? And how do they relate to keywords?

Spot the difference

Categories and tags are two built-in taxonomy systems in WordPress and, as such, they both group posts together based on a select number of relationships. Now, each should be used for their own unique kind of classification1. By getting a better understanding of what categories and tags are for and how they work, you can use them to organize your content and make your site more easily navigable for your visitors.


Categories are necessary; every single post you write needs a category. If you don’t assign any category to a post, WordPress will automatically set it into the “Uncategorized” default category. Actually, you could add multiple categories to a single post; however, it is best to assign only one category to each blog post.

Unlike WordPress categories, tags are optional. You can publish a post without tag. If you do make the decision to use tags, keep in mind that tagging should be limited only to the most relevant topics covered in the post2. In other words, although there is no (real) limit on how many tags you can add, it is best to assign between two and five tags per post.


Categories are hierarchical. This means that you can have a parent category with child categories (aka subcategories). Actually, WordPress allows up to three levels of categories to organize more complicated, hierarchical topics. Nonetheless, one layer of subcategories is probably all the farther you would want to take this particular taxonomy3.

Unlike categories, tags are non-hierarchical. They don’t have a parent-child relationship; each tag being a standalone item that has no level.

This is why you’re much more likely to use categories to structure your site than tags, as they have their own inherent structure.Rachel McCollin


While both categories and tags act as grouping systems, their use differs in one crucial respect: categories group broad topics of your posts while tags describe a specific detail in your content. Moreover, categories should align with the main topics covered on the rest of the site1; they are there to help identify what your blog is really about. On the other hand, tags are the perfect kind of taxonomy when generalities need to begin giving way to specifics3. They indicate the individual things that the post talks about.

A combined effort

Tags are not categories, they complement them.

Both taxonomies are different in their practical uses (see above) and it is important to abide by their intended purposes. Nonetheless, when used together – and when you do it right – they can create a better experience for your readers (and help boost your search ranking as well).

When executed properly your categories and tags should work with your blog topic and each individual post title to create a logical line from broad topic to unique article.Nathan B. Weller

Again, a category is what you determine to be the main topic of a post. Accordingly, blog posts should clearly fit into a single category. By contrast, you can add multiple tags to a single post; when read together, tags should somewhat sum up the idea of the post. However, if you find no obvious way in which you can tag a specific post, don’t tag it2.

you shouldn’t tag a page for the sake of tagging a page — you should do so because grouping posts by that particular tag could be of use to a reader.Tom Ewer

A corollary problem is that poorly thought-out categories often lead to tags being used to close the gap. While tags can complete the sorting you do with categories – by providing more details about the post content – they should not be used as sub-categories. In fact, tags are best used to create groups of content that apply to multiple categories. A situation where two (sub-)categories would have the same name is a good example of where tags might be a better choice.

To put it simply, WordPress categories should be used to group posts into as few sections and sub-sections as possible whereas WordPress tags should be used for recurring topics on your blog.Lyn Wildwood

What about keywords then?

As stated in the introduction, your targeted keywords must be scattered through your entire site’s content. That is in your post title, in the post itself (several times, if you can do so naturally), in the description and alternative text (i.e. alt attribute) of your images, and, of course, in your taxonomy!

Definitively, you should use keyword-rich categories and tags. In fact, not only should you include keywords in your taxonomy, but also you may consider doing extensive keyword research to optimize them. That being said, it is important to understand that your categories and tags are for organizational purposes. You may label them with keywords that readers would potentially search for, but you should not do so solely for the sake of SEO. Your taxonomy names should be relevant primarily to your posts. In other words, even though the best tag is also the keyword or keywords you’re targeting with your post3, you don’t want to create tags for the sole purpose of trying to cover all your SEO keyword bases.

Here come the infamous meta keywords.

First, let me reiterate that WordPress tags (i.e. taxonomy) are NOT meta keywords (i.e. HTML tag). Meta keywords are specific type of <meta> tags, which appears in the source code of a web page (inside the <head> element). Because they define keywords for search engines, they could have been a great feature for SEO – if not being abused by site owners and marketers.

People started spamming this keywords element and search engines began ignoring it.Joost de Valk

Accordingly, you should not waste your time on the meta keywords tag4; SEO-wise the latter is dead4. As a matter of fact, Yoast removed this functionality from their plugin (since version 6.3) and the title of their article on that matter says it all:

Why we don’t use them – and neither should you.

Granted, meta keywords may not be as prominent for SEO anymore; yet, I don’t see why you should avoid using them altogether. Nonetheless, the taking home message is that keywords should be integrated throughout your site, not just in this <meta> tag, which is disregarded by search engines’ crawlers anyway.

Wrapping up

Your goal is always to make your site as user friendly as possible. Categories and Tags are two taxonomy types that can help you organize your content and, in doing so, make it easier for your visitors to find exactly what they are seeking. As long as you are using them properly, this can ultimately help your SEO efforts as well.

Taking the time to use categories and tags correctly can boost your SEO, raise the average time-on-page of your visitors, and provide an overall better experience for your readers. The categories and tags you create become the skeleton of your website, clueing in both readers and search engines to its structure and content.KeriLynn Engel

Again, the sooner you organize your categories and tags, the better. As emphasized throughout this mini-series on WordPress taxonomy, the key to categorizing and tagging your content is rooted in the old contradictory axiom, ‘Less is more’2.

1 Brenda Barron (2018) WordPress Categories and Tags: what’s the difference and how to use them. wpmudev. ^
2 Tom Ewer (2012) The right way to use categories and tags in WordPress to boost SEO. ManageWP. ^
3 Nathan B. Weller (2014) WordPress Taxonomies: a guide for the average user. Elegantthemes. ^
4 Joost de Valk (2017) Meta keywords Why we don’t use them – and neither should you. Yoast. ^

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