WordPress makes use of taxonomy when grouping content but also other CMSs still use a similar system. Taxonomy for this case is used to refer to groups of websites and pages which share something in common. This makes it effective for users searching the same content to get similar articles more easily. The most used taxonomies in WordPress are tags and categories.
The items in your website should be divided into categories but if they are too many you further divide them into subcategories. The categories help your user and Google to obtain a sense from every content you write. Your main categories should be included in the main menu of your site. For example, if you are running a shirt’s clothesline then you should divide it into subcategories like short-sleeved, long-sleeved, casual shirts, and official wear.
The main difference between tags and categories is based on the structure. Categories have a hierarchy where you have subcategories and even sub-subcategories while tags lack a hierarchy. Adding tags to your site structure is very important. To get to understand, you may think of categories as the table of contents for your site and tags as the index. A tag could be a store for the clothesline named above. Tags should be minimal, do not add a unique tag to every article you write since it’s senseless. Your tags should group articles that belong together and you can use one tag at least twice. Your tags can be positioned at the bottom or sidebar of your page but ensure they are available for your visitors who might want to read more about a topic.