Categories versus tags usage
Both categories and tags are only for posts and not for pages. Categories are meant to broadly group your posts together, while tags are meant to describe specific details of your posts.
- Categories are usually used to group posts by a broader topic.
- Tags are usually used to describe the content of the post and add more detailing to your post.
Categories are required for all posts, while tags are not. So when you not choose a category WordPress has default “uncategorized” category. However, it is recommended to use both categories and tags to help your readers find your content easily without spending much of the time thinking about how to navigate.
Example for category can be like “product review” and for tags can be “dslr, travel camera, canon” etc.
You can choose to allow search engines to index and list both category archive pages and tag archive pages. But if you think tags are not optimized completed and may not help users much, then you can restrict to categories alone
Categories are hierarchical. It is advisable to have few major categories and have subcategories under the category rather than everything into broad categories. But it all depends on your niche, your blog content type and your readers.
Ideal scenario would be one category or sub category per post and 2,3 relevant tags.
Earlier tags used to be harnessed for its SEO benefits and now with more mobile readers tags are getting less significant