Larry Page and Sergey Brin incorporate Google Inc. The PageRank algorithm — ranking pages by the quality and quantity of links pointing to them — becomes the foundational signal of modern search.

Google's first major algorithm update aggressively targets keyword stuffing and manipulative anchor text. Thousands of sites lose rankings overnight. SEO as a profession is permanently altered.

Google Panda targets thin content, content farms, and low-quality pages at scale. Sites with high volumes of low-quality content are penalised. Content quality becomes a site-wide signal, not a page-level one.

Google Penguin targets manipulative link schemes — exact-match anchor text, paid links, and link networks. The black-hat link building era effectively ends for sophisticated practitioners.

Google introduces the Knowledge Graph — a database of entities and their relationships. Search begins understanding things, not just strings. Entity SEO is born.

Google Hummingbird rewrites the core search algorithm to understand conversational queries and semantic meaning, not just individual keywords. The shift from keyword matching to intent understanding begins in earnest.

Google reveals RankBrain — a machine learning system used to process unfamiliar queries. It is confirmed as one of the top three ranking signals. The era of algorithmic opacity begins: no human writes the rules anymore.

A broad core update heavily impacts healthcare, finance, and YMYL (Your Money, Your Life) websites. E-A-T (Expertise, Authoritativeness, Trustworthiness) emerges from Quality Rater Guidelines as the dominant quality framework.

Google deploys BERT (Bidirectional Encoder Representations from Transformers) to better understand natural language, particularly prepositions and context in longer queries. The foundation of transformer-based search is set.

Google's Helpful Content Update introduces a site-wide classifier targeting content written primarily for search engines rather than people. E-E-A-T (adding Experience to the framework) is codified. The content quality bar rises permanently.

Microsoft integrates GPT-4 into Bing, creating the first major AI-powered search product at scale. The traditional blue-link SERP is challenged for the first time by a credible alternative. GEO as a discipline is born.

Google launches SGE in Search Labs — an AI-generated answer overlay on search results. The AI Overview era begins. Zero-click search intensifies. Brands not cited in AI answers become effectively invisible for a growing share of queries.

Google rolls out AI Overviews to all US users and begins international expansion. AI-generated answers appear for hundreds of millions of queries daily. GEO and AEO become mainstream professional disciplines.

Search is now fragmented across Google AI Overviews, Perplexity, ChatGPT Search, Gemini, and Claude. Each surface has distinct citation preferences and crawl behaviour. Technical SEO, GEO, and AEO must be executed in concert. The brands that built entity authority early are compounding their advantage.