Tags are similar to categories, but they are generally used to describe your post in more detail.
Sample: For the wordpress training site I would use categories like WordPress Training
with tags like “Basic” “Intermedite” and “Advanced”
- Posted: WordPress Training
- Tagged: Basic, Intermediate, Advanced
The use of tags is optional (although each post must be attached to at least one category)
There is an advantage to using tags, it increases the change that other wordpress users will see your content.