Structured data helps search engines understand the meaning of content on a page. It is a standardized format that supplies additional information for classifying a page’s content.
Most search structured data typically follows schemas as laid out by schema.org, a community promoting their use for structured data on the Internet.
Every schema consists of one or more properties each having an expected data type and description of that data. A structured data testing tool is frequently used to ensure the structure can be interpreted as intended.
Although using structured data isn’t a ranking factor, its use can enhance a page’s appearance in search via rich snippets, a brand’s knowledge graph card, and inclusion in AMP and other Google services.
The most popular structured data formats are JSON-LD, Microdata, and RDFa.