There are the following type of tags:
Normal tags
Normal tags are the default tags when you create a new tag. Every time you create a new tag, a new tag page is automatically created. When you add a regular tag to an article, the tag is visible on the website below the article.
Sticky tags
Sticky tags are similar to normal tags, with the difference that sticky tags are added by default to every article you create. So be careful when creating sticky tags.
Internal tags
Internal tags are only used for internal use and are not visible on the website. Also, no tag page is created when you create an internal tag, so you can't add text. This type of tag is useful when you want to group a certain group of articles but don't want readers to see the tag on the website. With advertorials, for example.
Collection items
Collection items are tags that are part of a collection. These tags are the same as normal tags but are also shown on the collection page. You can only use these when you have created a collection