To understand how search engines work, we should do a little exercise in imagination. Let’s imagine for a moment that the Internet is the metro stations of a big city. Each stop has a unique document (usually a web page, but sometimes it can be a PDF, JPG image, etc.). Search engines need a way to traverse the entire city and find all the stops along the way, for this reason they use the best possible way: links.
If you have come to this class it is because you want to know how search engines work, we imagine that to do SEO. If the term SEO sounds like Chinese, you can review the previous class:
There are 3 fundamental concepts when it comes to understanding how search engines work: crawling or crawling, indexing or indexing and ranking. Do you want to know more? Well, we started!
What is crawling?
The structure of the links in a Web page serves to unite all the pages. The links allow search engines, through automatic robots called crawlers or spiders, to reach the billions of interconnected documents on the Web.
What the “robot” will do is access all the content it can through the links on your website. If there were any problem within the web, the robot could not access and that content could not be tracked by the search engine.
What is indexing or indexing?
Once search engines find the necessary pages, they crack the code and store certain information in databases, to be used later if needed in a search query. In order to carry out this monumental task of maintaining billions of pages that we can all access in a matter of seconds, companies like Google, Bing or Yahoo! They have built database centers all over the planet.
What search engines do is save a kind of “image” of your website, which they will access later if necessary.
What is the ranking?
When a user performs a search in any of the most popular search engines, the demand is instantaneous, even a delay of 1 or 2 seconds can cause dissatisfaction in the user, for this reason search engines try to provide a response as soon as possible.
Google (or any other search engine) will look at the information it has stored, will apply the algorithm of turn and will show the user a series of results. If we have done the SEO well, we will come out in the first position (or at least on the first page).
What happens if we change the URL structure of our website?
Remember that at this point the search engine in question already has the structure of our website indexed on their computers, so if they have not had time to crawl our website again, users could find a 404 page not found error.
It happens a lot that the URL structure of a website is not taken into account when changing or redesigning it. Changing the URL structure without notifying Google is a mistake that we should not make.
If you have to change the URL structure, it must be done by redirecting each old URL to its corresponding new URL, using 301 redirects. We recommend always keeping these redirects for at least 18 months.