Structured data is code that marks up a page's content in a defined format (usually Schema.org vocabulary in JSON-LD) so search engines and AI can read it accurately.
You pick a type to mark up: Organization for company information, LocalBusiness for a business location, Service for services, Article for articles and FAQPage for FAQs. People don't see it, but it keeps search engines and AI from being confused about what the page is about.
Since 2023 Google has shown FAQ rich results only for some authoritative sites, but FAQPage markup still helps machines understand a page's content.
