Which sequence best describes how a search engine operates?

Which sequence best describes how a search engine operates?

• A. The user enters keywords into a search bar; a web crawler searches the index for matching words; algorithms bring back the best results that include these terms; the results are ranked in order and the best are displayed on the computer; when a new website is found, it is added to the index so that it can be searched for
• B. The user enters keywords into a search bar; a web crawler searches the index for matching words
• C. The user enters a keyword; the DNS resolves the domain; the browser renders the page
• D. The user enters keywords; advertisements are shown; the first ad is clicked

Answer: (A)

Understanding how a search engine works begins with turning your typed keywords into useful results from an index. When you enter a query, the engine uses its index to find pages that contain those terms, which is faster than scanning the entire web in real time. Web crawlers explore sites and add new pages to the index so they can be searched later. The search algorithms then rank those pages by relevance and other factors, so the most useful results appear first. The results are displayed to you, and the index is continually updated as new content is found. This sequence—query, retrieve from index, rank, display, and update—best describes how a search engine operates. Other sequences miss key steps like indexing and ranking or mix in processes such as DNS resolution or advertising.

Understanding how a search engine works begins with turning your typed keywords into useful results from an index. When you enter a query, the engine uses its index to find pages that contain those terms, which is faster than scanning the entire web in real time. Web crawlers explore sites and add new pages to the index so they can be searched later. The search algorithms then rank those pages by relevance and other factors, so the most useful results appear first. The results are displayed to you, and the index is continually updated as new content is found. This sequence—query, retrieve from index, rank, display, and update—best describes how a search engine operates. Other sequences miss key steps like indexing and ranking or mix in processes such as DNS resolution or advertising.