Crawlers, also known as spiders or bots, are software used by search engines to scan websites.

What is a Crawler?

Crawlers, also referred to as web crawlers or spiders, are tools used by search engines to scan and index websites. Known as search engine bots, they are likened to spiders traversing the internet web, which is why they are named as such. These tools are crucial for website owners as websites are developed to enable these bots to perform more effective scanning. Proper scanning by crawlers is extremely important for SEO (Search Engine Optimization).

What Purpose Do Crawlers Serve?

Crawlers are used by search engines to scan websites and gather information to add to their indexes. Advanced search bots collect and process content from websites to provide direct answers in search results. When you ask a question on a search engine, it can respond by quoting content from websites in its index.

How Do Crawlers Work?

Crawlers scan websites starting from a known address, exploring all linked addresses and ensuring their addition to the search engine's index. It is essential for the search engine bots to know your website's address initially. If there is a link to your site from any other website or social media platform, search engine bots will find your site, although this might take some time. If you are a website administrator, you can inform search engines of your site's sitemap through panels designed for web administrators. For example, Google uses the Google Search Console application. A sitemap, which contains all the links on your site, helps bots navigate your site.

Bots reaching your website collect rules from the robots.txt file and meta data and schema data from your pages to add to their index. During this indexing process, your pages are scored according to unique evaluation criteria, and your ranking is determined. The search engine uses the content it collects from you and the scores it assigns to display search results to users.

What is the Difference Between Web Crawling and Web Scraping?

The scanning performed by web crawlers is called crawling. Web crawling (web scanning) is often confused with web scraping (web scraping), although these two concepts work in a similar manner but are used for different purposes.

Web crawlers are used to index websites. Visiting crawler software or search bots collect necessary information to add to their indexes by observing rules specified in the robots.txt file and various tags.

Web scraping, on the other hand, is used to collect content from a website. The content to be retrieved from a web page is determined, and scraping tools are tailored accordingly. Data from the web page can be gathered to be used elsewhere. Web scraping allows for the unauthorized use of data on websites, leading to a legal grey area. Moreover, scraping bots directed frequently and regularly to the source can negatively impact the website's operation."