Schema markup is microdata tags added to your website’s text content, which can help the way it gets displayed as a search result.
For example, if your business hosts events, schema markup added to the content specific to that event (time, speaker, location, event reviews and ratings, etc.) can get those events to show up higher in relevant searches.
Plus, the search results can include the details for the event that have been marked up.
Properly adding schema to your site could also earn you a rich snippet — a Google result packed with lots of quality info. Search Engine Journal offers some more powerful tips for utilizing schema.