Themes let you change your website’s appearance easily by applying a new set of templates, layouts, and styles over your content. You’re probably already familiar with this concept if you’re coming from some other CMS like WordPress.
In PieCrust, themes work better if you don’t have any templates – otherwise, you would end up mixing the theme’s appearance with your own, which (unless it was done specifically against a given theme) probably won’t work well.
Themes are really just normal PieCrust websites, but with a theme_config.yml
file instead of config.yml. You can easily install them, change them, or
create your own.