In the context of search engine optimization (SEO), “crawling” basically refers to a robot, better known as a Web Crawler, that automatically surfs the web, categorizing and analyzing each site it encounters. Crawlers basically gather and track URLs to prepare them for indexing. An index is another name for the database used by a search engine. By giving crawlers a webpage as a starting point, they trace all the valid links on those pages. As they go from link to link, they bring back data about those webpages back to the servers. Therefore, it is crucial that pages on your website are able to be crawled as a page unable to be crawled is unable to be indexed. The “LRT difference” is that LinkResearchTools (LRT) also crawls links that are blocked for other link crawlers. This is the reason why so many “deleted” links make sense for highly professional online marketers to crawl. Check out more about what LinkResearchTools.com can do for you.