What is crawler? How does it work?

Crawler is also known as a searching bot, or even sometimes called a web-spider. It is a software module for the searching systems. They are responsible for looking for the websites, their scanning and adding to the list of known sites.

Interesting! A searching bot is working not only by the human’s operating. It visits millions of websites with gigabytes of the texts on its own.

The main principle of working is close to web-browsers. On the first stage, the bot is analyzing the document. Then, it is saved in the data base of the searching system. After that, it goes to other sections by the links.

What are robots doing?

Well, people who have vague knowledge about the searching systems and searching bots are sure that such bots might have extra power. In fact, everything is simpler. They don’t have supernatural power. Every robot has its own function and performs it. It is like running a big factory where every worker does a certain operation.

Such bots can’t go into the website sections with passwords. They won’t be able to understand frame system processes, JavaScript and flash. In fact, all the functions depend on what basic function were installed in them by the developers.

Note! The speed of indexing and the frequency of visiting websites by the bots depend on the fact how regular the content is updated. If you want to help bot to index all the pages, you need to create maps of the site in two formats: .html and .xml

How is the searching output formed?

It works with three stages:

1. Scanning – search bots collect the contents of sites (texts, photos and videos).
2. Indexing – the robot enters the collected information into the database and assigns a specific index to each document. Materials can be in quick release for several days and receive traffic.
3. Output of results – each page takes a certain position according to the ranking results laid down in the algorithms of search engines.

Sometimes, leading companies, like Google make corrections in the bot running system. For example, they can limit the volume of scanning texts. They can also limit how deep the bot can scan the webpage. So, it leads to the fact, that webmasters have to adapt to these changes while using SEO-optimization. 

Every searching system has certain crawlers responsible for different functions. The number of them can be quite different, though, their functions is quite close.

How to handle searching bots?

Sometimes the owners of the websites are closing some sections of the websites from the bots. They do it because they don’t want certain content to be included in the search. All such commands are written in a special text file. It is called robots.txt.

It is a document that provides a list of documents for crawlers that can’t be indexed. The section can be really different. It can be connected with personal data or technical site elements. When the bot meets such commands, it analyzes them and leaves the forbidden section. 

Important! What to write in the file robots.txt? Here the owner states if he wants to open/close some fragments for indexing. Here the intervals between the queries can be also included.

How to know that the bot is visiting the website?

There are several ways to know that robots are visiting your website. One of the easiest is to use Google Analytics. It is just enough to authorize in the system. There you can see the results of visiting the page by the robots.

It is important to know if the website is included in the list of the searching systems. It is important for SEO-specialists to analyze the resources and move the page forward. Webmasters will always focus on the attempts to know how the crawlers are working. The process is almost unstoppable because they are constantly updating.