> ## 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.

# Entity ID

> An entity ID is a unique, persistent identifier assigned to an entity within a structured knowledge system — such as a Wikidata QID, a Google Knowledge Graph...

*Core concept* · *Entity & Knowledge Graph*

## Definition

An entity ID is a unique, persistent identifier assigned to an entity within a structured knowledge system — such as a Wikidata QID, a Google Knowledge Graph ID, or a schema.org identifier. It distinguishes one entity from all others with similar names and links its representations across platforms.

## Why It Matters for AI Search

AI systems resolve ambiguity by matching entity IDs across sources. When the same identifier appears on a brand's website, its Wikidata entry, and its schema.org markup, the system can confidently merge those signals into a single authoritative record. Without a stable entity ID, a brand risks fragmentation — its data interpreted as multiple partial entities rather than one coherent presence.

## Related Terms

<CardGroup cols={2}>
  <Card title="Wikidata QID" href="/ai-search-glossary/wikidata-qid" />

  <Card title="sameAs array" href="/ai-search-glossary/sameas-array" />

  <Card title="Entity record" href="/ai-search-glossary/entity-record" />

  <Card title="Knowledge graph" href="/ai-search-glossary/knowledge-graph" />

  <Card title="Entity verification" href="/ai-search-glossary/entity-verification" />
</CardGroup>

## Relevant Plate Lunch Collective Services

[Entity SEO](https://www.platelunchcollective.com/services/entity-seo)  [Context Map](https://www.platelunchcollective.com/services/context-map)