Search engines manage a heavy database of A. URLs B. web pages C. keywords D. All of these

The correct answer is D. All of these.

Search engines manage a heavy database of URLs, web pages, and keywords.

• URLs (Uniform Resource Locators) are the addresses of web pages.
• Web pages are the documents that are displayed on the World Wide Web.
• Keywords are the words or phrases that people use to search for information on the web.

Search engines use these databases to index web pages and to provide search results. When a user searches for a keyword, the search engine looks through its database of URLs and web pages to find the most relevant results.

The search engine then ranks the results based on a number of factors, including the relevance of the web page to the keyword, the popularity of the web page, and the quality of the web page.

The search engine then displays the results to the user in a list. The user can then click on the results to view the web pages.