English 
Русский 
简体中文 
Português do Brasil 
Français 
Español 
Türkçe 
Polski 
Tiếng Việt 
한국어 
Nederlands 
Italiano 
日本語 
Eesti 
Čeština 
മലയാളം 
Bahasa Melayu 
हिन्दी 
اردو 
Bahasa Indonesia 
Safe WebA web crawler, also known as a web spider, is a type of automated software program that browses the internet in a systematic manner in order to collect data and information. By crawling over web pages, it can extract and store structured information for later use. Web crawlers are commonly used for tasks such as indexing websites for search engine databases, data mining, and content extraction.
Web crawlers operate on the basis of programs that define the type of information to be retrieved and how to parse through the data. These programs are often written using programming languages such as Perl or Python, and can be limited in scope to crawl a single website or traverse the entire internet. Additionally, crawlers can be heavily customised to meet specific needs.
A web crawler’s primary function is to locate and grab web pages. Using a predetermined algorithm, it will search for web links starting with the initial address provided. Once the crawler finds a link, it will follow it to an adjacent page, and so on. This allows the crawler to crawl over hyperlinks and index web pages connected to the initial address.
Once the crawler finds the content it needs or reaches the end of the links, it will start to compile the data it’s gathered. During the compilation process, it will break down the retrieved web pages into their individual components in order to extract useful information. This process is known as web scraping. Once all of the data has been gathered, it will be stored in the appropriate format for later use.
Web crawlers can be beneficial for businesses, as they can save human resources by crawling websites automatically and gathering useful information. They can also be used to detect malicious activities, spam, scams, and outages.
In conclusion, a web crawler is an automated software program that browses the internet to locate and grab web pages, extract useful information, and store it for later use. Crawlers are used for different purposes such as indexing websites for search engines, data mining, and content extraction.
