Structured Data

Structured data annotates a page with explicit statements about its content: this string is a price, this one is an author, this block is a question and that is its answer. It removes the guesswork from parsing, which is the whole point — an engine reading prose infers, an engine reading markup knows.

It is not a ranking factor in itself. What it buys is eligibility for rich results and clearer entity understanding, and the first of those changes how much of a results page a listing occupies, which moves clicks even at an unchanged position.

The rule that keeps it out of trouble is that markup must describe what is visibly on the page. Marking up reviews that do not appear, or a price that is not offered, is a manual-action risk rather than a clever shortcut.