Algorithms play a crucial role in online search engines by determining how information is indexed and ranked based on user queries. These algorithms analyze various factors such as relevance, authority, and user engagement to deliver the most pertinent results. They utilize complex mathematical models and machine learning techniques to continually refine search results, enhancing users' experience. The effectiveness of algorithms in processing vast amounts of data influences the accuracy and speed of search engine results, making them essential for ensuring users find the content they seek quickly and efficiently.