Ghost has a flexible organisational taxonomy called tags, which can be assigned from post settings menu within the Ghost editor.
IV. Writing posts and pages
Ghost has a powerful visual editor with familiar formatting options, as well as the ability to seamlessly add dynamic content.
The post settings menu within the editor allows you to fully optimise your content. This is where you can add tags and authors, feature a post, or turn a post into a page.
There are several settings within Ghost Admin that allow you to make some of the most fundamental changes to your publication such as titles and descriptions, language, icons and social accounts.