Confluence has an easy way of defining page properties or variables on the page and then building various reports around it, https://confluence.atlassian.com/doc/page-properties-macro-184550024.html. Smart Templates takes this on the new level and allows you to connect these properties with variables inside your Smart Templates (with embedded contents) or directly to Confluence Templates (when Smart Template is set to use the Confluence template as a contents source provider)
Sounds complicated? I believe not. Let me explain...