What is a web crawler?
Web Crawler is the name given to web crawlers, also known as spiders. Basically its mission consists of constantly crawling the Internet, indexing the new sites created, the articles published and, ultimately, all the content that we can see through search engines.
Thanks to these trackers that index all this contentSimply by doing a search in Google we can find related results. We can solve doubts, find information to solve a problem, look for information that interests us … They are one of those essential elements that we talked about and that will help us to navigate the web correctly.
Therefore, Crawler or tracker is a bot, a set of thousands of them, which are constantly analyzing internet, indexing the sites, the pages that correspond to each website, the information they contain, the different sections … All of this is linked to the searches that the end user will carry out in services such as Google, Bing and any other similar.
Crawlers control millions of pages
But if we think about the vastness of the Internet, we can say that the crawlers are going to control thousands, hundreds of thousands, of websites of all kinds. If we make a common google search, there are millions of pages that can have those terms. It would be impossible on a human level to track everything and come up with the one that really best suits what we are looking for.
Therefore, what a web crawler does is select the best content of everything that has been indexed and that best adapts to what we have searched for. These bots will be permanently crawling the web to detect any minimum changes and to be able to create a list, a large database, to show the best results at a given moment.
This makes it possible for us to affirm that web crawlers are essential today. The Internet as we know it would not be possible without search engines. We would always tend to visit the same places we know by heart and where, hopefully, we find the information we are looking for. Instead, thanks to these bots, simply by searching for a phrase or a term in Google we can reach many sites that help us solve a certain issue.
Great value for webmasters
There is no doubt that web crawlers are of great value to those responsible for web pages. At the end of the day, when someone decides to create a website, they will have the goal of receiving visits, having an audience and reaching as many users as possible.
Thanks to these trackers, that web page will be available to users who reach it through search engines. Otherwise it would be like having a store in a basement without a door and without a sign, and expecting customers to arrive.
It is a fact that they have a fundamental role in our day to day when it comes to surfing the Internet. At least the way we currently use the network would be greatly affected if there were no web crawlers.
Now, is all content on the Internet indexed by web crawlers? The answer is no. In fact there are many websites and content on the net that we will never be able to access directly from search engines. This can occur for different reasons as we are going to explain.
The person in charge of a website does not want it to appear
One of the reasons a website can be hidden from the web crawler it is because the person behind that page does not want their site to appear in search engines. This is something that can happen on certain occasions. If they have not been tracked, logically they will not appear when we perform a search.
Why can this happen? Perhaps within a website there are certain sections or pages that you do not want to be indexed. It is simply information that is there, which visitors can access directly from links within the web, but it is not published in search engines.
The site has not yet been indexed
It can also happen that a web page is recently and has not yet been traced. The web crawlers have not yet arrived and therefore they have not added it to their list so that it appears in Internet search engines and that it is available to users.
The crawlers are constantly analyzing the pages that are on the net. However, not in all cases they do it at the same time, or with the same speed. The most recent sites, the ones that carry even less weight on the Internet, can take even weeks to index the content. This makes it hidden from search engines during that period of time.
Pages on the Deep Web
Another type of websites hidden from search engines are those found in the Deep web. This is how the entire hidden part of the network is known, which is precisely not available to search engines. It should not be confused with Dark webas they are different terms.
To access the content of the Deep Web it is necessary to use certain browsers like Tor. We cannot find the .onion sites, which are those that are related to the Deep and Dark Web, simply by accessing through Chrome, Firefox or any conventional browser. We also won’t find those websites by searching Google.
Therefore, as we have seen, web crawlers are very important for the proper functioning of the Internet. They are essential for crawling and indexing the websites on the net. Without them we could not use search engines like Google to get to the content we want to find. They are vital in this regard, although we have also seen that in certain circumstances the pages may be hidden and not appear in search engines.