Crawling is the process by which search engines like Google, Bing, and Yahoo! search the web for new or updated content. It involves automated software tools called spiders, which systematically crawl websites by following links from one page to another.
When a spider visits a website, it reads the content of each page and follows links to other pages within the site. This process continues until all pages on the site have been crawled. The spider then sends the information it has collected back to the search engine, which uses it to update its index.
Crawl rate refers to the frequency at which search engines crawl a website. Websites with high-quality content and frequent updates are crawled more often than those with low-quality content or infrequent updates.
Indexing is the process by which search engines organize and store information they have collected during crawling. This information is used to provide relevant results when users perform searches.
A sitemap is a file that lists all of the pages on a website. It helps search engines find pages that may not be easily discovered during crawling. Including a sitemap in your website can improve your website's visibility and increase its chances of being indexed.
Robots.txt is a file that tells search engine spiders which parts of a website they are allowed to crawl and index. By using robots.txt, website owners can prevent search engines from indexing certain pages or sections of their site.