JSON-LD

JSON-LD keeps structured data in a single script tag in the head or body, separate from your visible HTML, which makes it far easier to maintain than the inline microdata it replaced. The cardinal rule is that the markup must match what users actually see on the page — marking up a 5-star rating that doesn't appear anywhere is a guidelines violation that can lose you rich results entirely. Validate every block with the Rich Results Test before deploying, since a single syntax error can invalidate the whole object.