> ## Documentation Index
> Fetch the complete documentation index at: https://wiki.platelunchcollective.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Web Annotation

> Web annotation is the practice of adding structured metadata or markup to web content to make its meaning and context explicit for AI systems and linked data...

*Technical implementation* · *Structured Data*

## Definition

Web annotation is the practice of adding structured metadata or markup to web content to make its meaning and context explicit for AI systems and linked data applications. It encompasses schema.org markup, RDFa, JSON-LD, and other semantic enrichment techniques that convert plain web content into machine-interpretable data.

## Why It Matters for AI Search

Web annotation is the broader category that all structured data implementation belongs to. Every piece of schema markup, every sameAs link, every semantic HTML element is a form of web annotation — adding machine-readable meaning to content that would otherwise require AI systems to infer context from prose. A fully annotated entity page — with Organization schema, sameAs links, author schema, and semantic HTML — is maximally readable to AI crawlers.

## Related Terms

<CardGroup cols={2}>
  <Card title="Structured data" href="/ai-search-glossary/structured-data" />

  <Card title="JSON-LD" href="/ai-search-glossary/json-ld" />

  <Card title="RDFa" href="/ai-search-glossary/rdfa" />

  <Card title="Linked data" href="/ai-search-glossary/linked-data" />

  <Card title="Schema markup" href="/ai-search-glossary/schema-markup" />
</CardGroup>

## Relevant Plate Lunch Collective Services

[Entity SEO](https://www.platelunchcollective.com/services/entity-seo)  [AI SEO](https://www.platelunchcollective.com/services/ai-seo)