The implementation of structured data is of great importance in search engines because they provide an opportunity to make the results richer and visually more convincing. Schema markup are structured data that initiate good search engine rankings.
Search engines to better understand you through schema markup get information about your site and in return search engines give rich snippets about your page in the results.
These markups can be implemented using different languages of code - including RDFa, Microdata and JSON-LD. Things like rich cards, rich snippets, and the knowledge graph appear on SERPs after gathering information from structured data.
Numerous SEO sites provide free schema markup generators: TechnicalSEO.com, Googles Structured Data Helper, Schemaapp.com, MicrodataGenerator.com