The search engine robot is responsible for crawling web pages. The program automatically reads data from all sites and registers them in a form that is understandable for the search engine itself, so that the system will subsequently display the most suitable results for the user.
Functions
All indexed information is recorded in a common database.
A search robot is a program that automatically travels through the pages of the Internet, requesting the necessary documents and receiving the structure of crawled sites. The robot independently selects the pages to be scanned. In most cases, sites to scan are randomly selected.
Bot types
An improperly functioning robot significantly increases the load on the network and the server, which can cause the resource to be unavailable.
Each search engine has several programs called robots. Each of them can perform a specific function. For example, at Yandex, some robots are responsible for scanning RSS news feeds, which will be useful for indexing blogs. There are also programs that only search for pictures. However, the most important thing is the indexing bot, which forms the basis for any search. There is also an auxiliary fast robot designed to search for updates on news feeds and events.
Scanning procedure
Another way to prevent crawling of content is to create access to the site through the registration panel.
When visiting the site, the program scans the file system for the presence of robots.txt instruction files. If there is a document, the reading of the directives written in the document begins. Robots.txt can prohibit or, conversely, allow scanning of certain pages and files on the site.
The scanning process depends on the type of program. Sometimes robots only read the page titles and a few paragraphs. In some cases, scanning is done throughout the document depending on the HTML markup, which can also work as a means for specifying key phrases. Some programs specialize in hidden or meta tags.
Adding to the list
Every webmaster can prevent the search engine from crawling pages through robots.txt or the META tag. Also, the site creator can manually add the site to the indexing queue, but adding it does not mean that the robot will immediately crawl the desired page. To add a site to the queue, search engines also provide special interfaces. Adding a site significantly speeds up the indexing process. Also, for quick registration in a search engine, web analytics systems, site directories, etc. can be used.
