Guide to crawling, the basis of Google and SEO
It all starts here: without crawling, there would be no search engines as we know them, and therefore no ranking nor, clearly, SEO. In short, it is on crawling and the visits made by bots that the functioning of the Web (and our work to gain online visibility) is based, and this alone should make us realize the importance of knowing at least superficially about this topic, as we try to do with this guide to crawling for SEO.
What is crawling for search engines
Essentially, crawling is the discovery process during which search engines send a team of robots, called crawlers or spiders, into the Web to find new and updated content, which will then be added to the various search engine indexes.
The type of content is broad and can vary-a Web page, an image, a video, a PDF, and so on-but regardless of the format, content is discovered through links, whether they are on already known pages or through sitemaps that a site provides directly.
In English, the activity is called crawling: in technical terms it precisely identifies the entire process of accessing a website and retrieving data obtained through a computer program or software. That is, through the work of bots (usually known as crawlers or even spiders because, like spiders, they follow the path traced by link threads to create the Web) that automatically search or update web pages on behalf of the search engine.
As we said, this step is essential for every single Web site: if our content is not crawled, we have no chance of gaining real visibility on search engines, starting with Google.
Crawling: what it is and how it works for Google
Dwelling precisely on how crawling works for Google, crawling represents the search engine’s way of figuring out what pages exist on the Web: there is no central registry of all Web pages, so Google must constantly search for new and updated pages in order to add them to its list of known pages.
The crawling process begins with a list of URLs from previous crawls and sitemaps provided by site owners: Google uses web crawlers and specifically Googlebot (the name by which its program is known to perform the retrieval operation through the work of a huge amount of computers scanning billions of pages on the web) to visit these addresses, read the information they contain, and follow the links on those pages.
The crawlers will revisit the pages already in the list to see if they have been changed and will also scan the newly detected pages. During this process, crawlers have to make important decisions, such as prioritizing when and what to crawl, making sure that the website can handle the server requests made by Googl