WordPress uses categories and tags to organise related content. In the WordPress ecosystem, they’re called taxonomies. You only use categories and tags on posts. You can’t use categories or tags on pages.
If you don’t understand the difference between posts and pages, read this: In WordPress, What’s the Difference Between Posts and Pages?.
Categories cover very broad topics and exist so you can group your content together. When you first start a site, you might want to add your content to the top-level category only. As you add more content and your blog gets bigger, you can start creating subcategories and move your content across so your site makes more sense when people view the archives.
This is another reason why we don’t have the name of the category in the permalink – we can move posts from one category to another without affecting the URL.
Underneath categories, you the option to create subcategories.
Let’s use digital photography as an example.
If you have a site about digital photography, you would almost certainly have a category called digital photography. However, the topic is so broad, it makes sense to add more categories so people can easily find the topics that interest them.
Here are a few examples of categories you would expect to see on a digital photography website.
- Travel photography
- Portrait photography
- Landscape photography
- eBay photography
- Photography equipment
- Smartphone photography
Subcategories of the travel photography category would look something like this:
- Travel photography
- Travelling light
- Photography bags
- Local customs
- Planning a trip
If you use categories as part of your permalink structure, adding more subcategories increases the length of the URL. For example, on this site, we don’t use the category in the permalink. This keeps the URL short, which may or may not improve search engine rankings.
Here’s the format for our permalinks:
If we did use the category name in the permalink and we published a post in the top-level category, the URL would look like this:
If we used a subcategory and published a post in that subcategory, the URL would look like this:
When you’re creating content for your site, keep the following in mind:
- Every post must fit into at least one category, but you can add a post to multiple categories.
- Adding tags to a post is optional but advisable.
- Pages stand alone. You can’t add them to a category and you can’t add tags.
WordPress calls top-level categories ‘Parent(s)’ and the subcategories ‘Child(ren)’.
The default WordPress category is Uncategorized. You can change the default category by navigating to Settings in the left-hand menu, then Writing, and choosing the new default category from the drop down menu (here’s a tutorial).
It is a good idea to do this as some themes display category and tag links within each post, and assigning posts to a category called ‘Uncategorized’ may be perceived as unprofessional (to some) and won’t help people find related content.
Unlimited Categories ?
I’d like to say you can create as many categories as you like, and you can create unlimited subcategories too, but I’m sure there must be a limit somewhere within the software. It could be a crazy number like 10,000. I don’t know…
What About Tags?
Think of tags as keywords or keyword phrases related to your post.
As with categories, you can use as many as you like, but using too many can look ridiculous if they are all visible to your readers.
The main purpose of tags is to make it easier to find and curate similar content. Many themes display a list of tags and categories in link format at the bottom of each post, like this (from Photobomb):
Clicking any tag link displays the archive of all posts using that tag.
Tags and categories also serve another purpose – they’re used by plugins to look for related content to show at bottom of your posts.
Take a look at the bottom of this post to see what I mean. The heading is “Possibly Related Posts“.
Used properly, these plugins give your readers further reading options when they reach the end of an article and are a good way to keep people on your site.
Related posts plugins compare tags and categories and use the results to display related content.
Adding tags to WordPress is as simple as entering a word or two and clicking the Add button.
Remember though, separate each tag with a comma:
Adding Tags to a Post
Start typing a word for a list of tags you’ve already created:
Highlight the tag you want to use and click it to add it to your post:
Alternatively, click on the Choose from the most used tags link to get a list of your most used tags. Mine looks like this:
Click on the tags you want to add.
The list looks like this:
To remove a tag, click on the x (marked with an arrow).
If you want more control over categories and tags you can manage them through their own admin areas, accessible through the posts menu:
This is area is for only for management and monitoring. You can’t add tags to a post or assign a post to a category from here, you instead have to open the post to make your edits.
The Tags Widget
WordPress has a tags widget which you can place in your sidebar or footer. It displays a list of your tags in a cloud format. These are also known as tag clouds. The size of the text used in a tag cloud differs in size, from quite small to very large. The reason for this is the amount of times you use a tag; the more you use it, the larger the text.
Should you use one on your site? It’s a personal choice.
Here’s Matt Cutts, head of Google’s webspam team talking about the SEO benefits/problems associated with tag clouds.
Personally, I prefer not to use a tag cloud as I find them a little gimmicky and not much use to the end-user.
By default, WordPress includes 45 tags in the tag cloud, that’s an extra 45 links on every page displaying it. As Matt says in the video, all the extra links dilute any PageRank passing through to other pages.
Well done on reaching this far, I hope your head isn’t hurting too much? I’ve tried explaining categories and tags as simply as possible, but I know they can sometimes cause confusion, especially for beginners.
If you have any questions about this subject, or if you have something to add, please use the comment section below.