As the opening paragraph explains...

RDFa is an extension to HTML5 that helps you markup things like People, Places, Events, Recipes and Reviews. Search Engines and Web Services use this markup to generate better search listings and give you better visibility on the Web, so that people can find your website more easily.

Have a look at: Linked data in HTML5, https://rdfa.info/

Worth considering how your developers are developing your web site...