Microdata & Structured Data
Search engines parse a page's text well enough, but structured data goes further: explicitly labelling what kind of thing a piece of content is (a recipe, a product, an FAQ, an article) using a shared, standardised vocabulary — schema.org — that search engines specifically look for and reward with enhanced result displays.
What Structured Data Actually Buys You
That star rating and metadata row is a "rich result" — search engines only show this for pages with valid structured data describing the content as a Course or similar type. Without it, the exact same page shows only as a plain text snippet, regardless of how good the actual content is.
JSON-LD — The Recommended Format
Schema.org data can be embedded three different ways historically (microdata attributes directly in HTML tags, RDFa, or JSON-LD) — Google explicitly recommends JSON-LD today, since it's cleanly separated from the visible markup and far easier to generate and validate correctly.
This block lives in <head> (or anywhere in <body>) and is never displayed to visitors at all — it exists purely for search engine crawlers and other automated tools to read.
Microdata — The In-Markup Alternative
The older alternative embeds the same vocabulary directly as attributes on the visible HTML elements themselves — still valid, but generally considered messier to maintain than a separate JSON-LD block.
Common schema.org Types Worth Knowing
- Article / BlogPosting — for written content, enables author/date display in results.
- FAQPage — for question/answer content, can produce an expandable FAQ display directly in search results.
- Recipe — enables rich recipe cards with cook time, ratings, and ingredient previews.
- Product — enables price, availability, and review star display.
- BreadcrumbList — shows a breadcrumb trail (Home › Linux › Performance) in the search result URL line itself, instead of a raw URL.
- Course — used in the example above, relevant directly to osztromok.com's actual content.
<details>/<summary> pairs and a matching FAQPage JSON-LD block describing the same questions and answers is a genuinely common, complementary real-world pairing — the visible HTML serves users, the structured data serves search engines, both describing the identical content.
Validating Structured Data
Google's Rich Results Test (and the more general Schema.org Validator) checks a URL or pasted code against the actual schema definitions, flagging missing required properties and genuine syntax errors — directly analogous to Fundamentals Chapter 10's W3C validator, but specifically for structured data rather than HTML markup itself.
Chapter 9 Quick Reference
- Structured data — explicitly labels content type using shared schema.org vocabulary, enabling rich search results
- JSON-LD — recommended format; a separate <script type="application/ld+json"> block, invisible to visitors
- Microdata — older alternative, woven directly into visible tags via itemscope/itemtype/itemprop
- Common types: Article, FAQPage, Recipe, Product, BreadcrumbList, Course
- FAQPage + details/summary — a natural, common real-world pairing (Chapter 8)
- Validate with Google's Rich Results Test or the Schema.org Validator
- Never claim content that isn't genuinely visible on the page — mismatched structured data can trigger search engine penalties
- Next chapter: forms + JavaScript — client-side validation hooks, FormData