Schema markup is a code that can live in each of your webpages. This provides eligibility for what Google calls, "Rich Results". These are the dynamic elements seen in search results. A common type of rich result is a "Review Snippet", but there is schema for local events, county data, Q&A, fact check, videos etc. Because these results draw far more attention than the typical blue link, containing this code on your website can greatly improve your click thru rate in the SERP.