When creating posts, if you are confused about how to use Categories and Tags, perhaps this post will help.

By selecting Add Post or Editing an Existing Post, you will see the following interface:

Here you will have the option to select Categories your post belongs to as well as declare several Tags. This can be confusing to the beginning blogger, but using Categories and Tags correctly can greatly improve the experience of your blog’s visitors.

Categories are a useful way to provide thoughtful structure to your blog. Posts of similar content should be categorized under the same Categories.

Example: If you were to post many recipes on your blog, you could have each recipe belong to a category such as “Main Dish”, “Side Dish”, “Desserts”, “Drinks”, “Salads”, “Soups”, etc. and every recipe could belong to a general “Recipes” Category.  This way someone interested in finding a good dessert recipe could view at just your post under the Dessert category.

Tags are keywords found in your post content. 

Example: A recipe post for Banana Cream Pie may use the keywords: banana, pie, dessert, award winning, easy bake, low calorie.

Note: Tags will appear in the Tag Cloud view in the sidebar of your blog.