What it is
Schema.org is a shared vocabulary of structured data types for marking up web content in a machine-readable way. It is maintained by a collaboration of major search engines (Google, Microsoft, Yahoo, Yandex) and is the standard for SEO and AEO schema work.
Identifiers
Why it matters
Schema markup is one of the highest-leverage AEO tactics. FAQPage, DefinedTerm, Article, Person and all give answer engines clean signals about what a page is, who wrote it, and how it fits into a broader knowledge graph.
The underlying problem it solves is ambiguity. A machine reading your page sees text; it has to infer that a string is a company name, that another is a job title, that the two are connected. Schema removes the inference. You state the relationships outright, so there is nothing to guess at and nothing to get wrong.
Basics
is usually implemented as JSON-LD embedded in the page. Common types for content sites: Article, FAQPage, Person, Organization, WebSite, DefinedTermSet. Deploying schema at scale generally requires a plugin or a code-level approach rather than page-by-page editing.
The types that carry the most weight
Organization and Person establish who is behind the content — the foundation for any credibility signal, and the anchor other markup refers back to.
Article ties a piece of content to its author and publication date, which is how a machine tells current guidance from a decade-old post.
FAQPage maps question to answer explicitly, which is the exact structure an answer engine is trying to reconstruct anyway.
DefinedTerm and DefinedTermSet turn a glossary into a set of citable entities rather than a page of bold words.
BreadcrumbList describes where a page sits in the site’s hierarchy, so its relationship to the parent topic is stated rather than inferred from a URL.
What this means for your content
Mark up what is actually on the page — schema that describes content a visitor cannot find is a liability, not a shortcut. Use one consistent identifier for your organisation across every page so the graph resolves to a single entity instead of several. Connect the nodes: an Article should name its Person author, and that Person should belong to the Organization. Isolated markup describes a page; connected markup describes a business.