What is JSON-LD (Structured Data)?
A format for embedding machine-readable metadata in web pages so search engines understand the content and display rich results.
JSON-LD (JavaScript Object Notation for Linked Data) is Google's preferred structured data format. You add a <script type='application/ld+json'> block containing a JSON object that describes the page using schema.org vocabulary. This enables rich results in Google: FAQ dropdowns, breadcrumb trails, pricing cards, HowTo steps, and article metadata.