Search algorithms rank results based on multiple factors, including relevance, authority, and user engagement. Relevance assesses how closely the content matches the search query, while authority looks at the site's credibility and trustworthiness, often determined by backlinks. User engagement metrics, such as click-through rates and dwell time, indicate the quality and usefulness of the content to users. Search engines continuously update their algorithms to improve search quality, incorporating machine learning techniques for better predictions of user intent and preferences.