Instructs visiting spiders not to index the page, and/or not to follow its links to other pages. Some robots disregard this tag and index at their discretion. Other spiders may index the pages regardless, but not report found links to their search engine.

Web Robots (also known as Web Wanderers, Crawlers, or Spiders), are programs that traverse the Web automatically. Search engines such as Google use them to index the web content, spammers use them to scan for email addresses, and they have many other uses.