Web crawling, also known as web scraping, is a process by which software programs called crawlers or spiders systematically browse the internet in search of specific information. These crawlers gather data from websites and store them for future use by other applications. In this post, we will discuss what web crawling is all about and answer some of the most common questions related to this technique.
In simple terms, web crawling refers to an automated method of collecting data from websites through their various URLs. The crawler program moves from one website to another using hyperlinks found on these sites until it has covered a large part of the internet.
The crawler software starts with one or more starting pages known as seeds. From there, it follows links present on those pages that point to other relevant pages within the same domain or outside domains. When it finds new links on these secondary sites, it follows them as well.
Crawling Frequency: This refers to how often your site gets visited by Google's bots.
XML Sitemap: An XML sitemap helps crawlers understand your site structure so they can better crawl and index content.
Robots.txt file: Used for controlling bot access to a website via robots exclusion protocol (REP).
Crawl Budget: This term refers how many pages Googlebot will crawl over time.
Crawling Errors: Refers errors encountered while attempting discover page informations.
Websites use web crawling for several reasons such as data mining, research works including indexing website information used for ranking purpose by search engines like google etc…
While technically not illegal per se ,some factors must be taken into considerations when enabling scraping mechanisms thus lawyer advice might be needed.
To achieve effective web crawling, one needs to ensure that the crawler program is well-designed and capable of handling large amounts of data. Other tips include respecting robots.txt rules, detecting and fixing 404 errors as fast possible, using proxies when necessary.