Let’s see what the differences between WordPress Categories and Tags are. It is something basic but it is important to know it.
Categories in WordPress
Categories are a way of organising your WordPress posts (entries, articles). We should not confuse them with other types of categories, such as the “Product categories” that may appear when we install WooCommerce, for example, because those have nothing to do with it.
Categories have certain peculiarities. The first is that they are hierarchical. That means that there can be categories WITHIN other categories. For example, if we are a newspaper and one of our categories is “Sports”, a subcategory could be “Football”. Or in the category “International” there could be a subcategory “Germany”.
The categories and subcategories affect the construction of the URL. So, in the case mentioned in the example, we could have a URL like this:
Note that the categories and subcategories (in red) indicate the dependence on each other. On the other hand, we have what is called the “base category”, which we can see in green in the example. This can be changed in “Settings / Permalinks“. If for example we put “news” it would look like this:
If you want to continue learning about WordPress, I recommend this post about WordPress images and how it works.
So, it is important that when you choose a distribution of categories and subcategories you do not touch it, because as you can see, that would change the URLs, which Mr. Google does not like too much, because it will start to deindex those that it no longer finds. And if we have to do it, we should always do it with the corresponding 301 redirects.
As I say, categories are basically used to organise the content of the blog, and although there are no rules about how many there should be, they are usually few and limited. Let’s say a range of 5 to 10, more or less. This is for organisational reasons. Imagine a newspaper with 80 sections? It would be a mess, wouldn’t it?
Although in principle an article can be assigned to several categories, it is not very advisable, and should be chosen only for the main one, to ensure that we will not have problems of duplicate content. That’s because it is normally recommended to index and position the categories for SEO and positioning.
Tags in WordPress
On the other hand, we have the labels. More dynamic, more anarchic, more rebellious. And above all, more. A lot more. Unlike categories, tags are not hierarchical. That means that you can’t create a subtag that depends on another one. They are all at the same level. Like categories, they also have their own URL, to list all the articles that are tagged with it. In this case, and following the previous simile, it could look something like this:
As you can see, in this case there are no sub-levels, but we do have the “base tag” that does the same as the base category, that is, adding a text before the category.
By default this text is “tag”. Let’s not leave it like that, which is a pity, and put something more appropriate:
We can have hundreds or even thousands of urls, depending on our situation. That means hundreds or thousands of URLs with very similar content, and that is why it is not recommended to index them in search engines, that is, not to position them or SEO them.
In short, think of categories as if they were big sorting folders in which you store documents, and labels as if they were those colored post-its that you can place on each document.
I advise to Index the categories.
I do not recommend indexing Tags.
I hope it helps!