Search engine

A search engine is an information retrieval system that indexes the World Wide Web and responds to user queries with ranked lists of relevant documents. It operates through three stages: crawling (discovering pages by following hyperlinks), indexing (building inverted maps from terms to documents), and ranking (ordering results by relevance signals such as PageRank and query-term matching). The search engine is not a neutral mirror of the web; it is a curator that shapes what is findable, and therefore what is knowable. The algorithmic ranking of results is a form of editorial judgment exercised at scale, and the opacity of that judgment — the fact that ranking algorithms are proprietary and unpredictable — makes the search engine a locus of epistemic power.