HTML tag tells robots not to index the content of a page, and/or not scan it for links to follow, keeping this metatag for pages which we don’t want to index, nor to follow the links on the webpage is helpful.

In some cases, we come across situations where we keep links to external sites. But what are the impacts of this?

1. Part of page rank is shared to external website -
   When we link to other websites, our part of our website page rank is shared to
   those external sites, and we may end up sending the search engine crawlers to other side.
2. Leading Search Engine Crawlers to crawl external website -
   Crawler entered our website to crawl more pages, it will help us to have more indexes in Search Engines, but what did we end up keeping external links, we created a way to Crawler to leave our website and crawl the external websites.

We have to keep external links, but how do we prevent the above scenario -