Google’s web crawlers follow links and sitemaps in order to generate a list of publicly available URLs that we should visit. This is the first step in the process of being added to Google’s search results. Fetch Google fetches, or requests the bytes, for a resource (a page, an image, a video) during crawling. Index More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.