A search engine is a complex software system designed to search the World Wide Web systematically for specific information specified in a textual web search query. The search results are generally presented in a line of results, often referred to as search engine results pages (SERPs).
Google is the dominant search engine globally, handling over 90% of all queries, followed by Bing, Yahoo, and DuckDuckGo. Search engines use automated 'crawlers' or 'spiders' to discover web pages, index their content, and apply algorithms to rank them based on relevance and authority.