As I write blog posts myself, this is a question I’ve typed into Google recently.
Google introduced me to WP Beginner. Scanning through, I thought this was handy to share:
EG: Personal blog where you write about your life. Your categories can be: Music, Food, Travel, Rambling, and Books.
Now when you write a post about something that you ate, you will add it in the Food category. You can add tags like pizza, pasta, steak etc.
One of the biggest difference between tags and categories is that you MUST categorize your post. You are not required to add any tags. If you do not categorize your post, then it will be categorized under the “uncategorized” category.