> ## 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.

# Passage Indexing

> Passage indexing is the practice of storing and retrieving individual passages of a page rather than the page as a whole.

*Core concept* · *AI Search Infrastructure*

## Definition

Passage indexing is the practice of storing and retrieving individual passages of a page rather than the page as a whole. A search system splits content into passages, indexes each one, and can return a single passage as an answer even when the rest of the page is unrelated. It decides whether a passage exists as a retrievable unit at all.

## Why It Matters for AI Search

A model answers from a passage, not a URL. Passage indexing is why a single well-formed paragraph can be cited from a long page, and why a strong page with no cleanly separable passages can go unused. It is distinct from passage ranking, which decides the order among passages already retrieved. Indexing decides whether the passage is retrievable in the first place. Structuring content into self-contained passages is what makes it indexable at this grain.

## Related Terms

<CardGroup cols={2}>
  <Card title="Passage ranking" href="/ai-search-glossary/passage-ranking">Distinct from</Card>
  <Card title="Chunking" href="/ai-search-glossary/chunking">See also</Card>
  <Card title="Passage-level optimization" href="/ai-search-glossary/passage-level-optimization">See also</Card>
  <Card title="Semantic search" href="/ai-search-glossary/semantic-search">See also</Card>
  <Card title="Quotability" href="/ai-search-glossary/quotability">See also</Card>
</CardGroup>

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