In order to add/delete a category in your blog, log in to the admin area and go to Posts -> Categories. To add a category, simply type its name in the Category Name field. If you wish, you can also type a category slug, description and choose a parent item. Then click Add Category and your new category will be created.
Hereof, what is the use of category in WordPress?
Category is one of the pre-defined taxonomies in WordPress. It is used to sort and group content into different sections. A website publishing content on a variety of topics can divide their website into sections using categories.
What are categories on a blog?
A blog category is a topic you address on your blog. Your category list is like the table of contents for your blog. Categories are broad and can encompass smaller, more defined topics (i.e., tags). If categories are your blog's table of contents, tags are your blog's index.
How do I add tags to my WordPress blog?
To add tags to a new post, go to your blog's admin area > Posts > Add New. When you write your new post, you can add a tag to it by typing the tag word in the Tags field on the right and clicking the Add button. You can add as many tags as you want.