## TL;DR
AI-powered search represents the most significant disruption to information retrieval since Google. Perplexity's answer engine and Google's AI Overviews synthesize information rather than linking to it — fundamentally changing how billions access knowledge.

## Core Explanation
Traditional search: query → ranking algorithm → 10 blue links. AI search: query → retrieval → LLM synthesis → cited answer. Two architectures: retrieval-then-generate (Perplexity: search first, then generate answer) vs integrated (Google: blend search results with AI-generated summaries in the same interface).

## Detailed Analysis
Perplexity's pipeline: real-time web crawling → relevance filtering → chunk selection → LLM summarization with inline citations. Key challenges: citation accuracy (cited sources must actually support the claim), freshness (news needs real-time indexing), and business model (how to monetize answers vs clicks).

## Further Reading
- Perplexity AI Blog
- Google AI Blog: Search
- NeuraSearch: AI-Powered Search Research