what is crawlers?

what is crawlers? how it's work?

Crawler – The program is automatically to follow the links are web page..

A crawler is a program used by search engines to collect data from the internet. When a crawler visits a website, it picks over the entire website's content.

Crawlers, also known as Google Bots or Spiders, are nothing but software programs that are designed to crawl, index, rank and return your site from the search engine database.

A crawler is a program that visits Web sites and reads their pages and other information in order to create entries for a search engine index

Search Engine Crawler is a program that is automated and browses the web to provide data to a search engine.

Crawling is the process search engines discover updated content on the web, such as new sites or pages, changes to existing sites, and dead links.
To do this, a search engine uses an algorithm that can be referred to as a 'crawler', ‘bot’ or ‘spider’ which follows an algorithmic process to determine which sites to crawl and how often. As a search engine's crawler moves through your site it will also detect and record any links it finds on these pages and add them to a list that will be crawled later.
This is how new content is discovered.

A web crawler is also known as a web spider or web robot is a program which browses the World Wide Web in a methodical, automated manner.Web crawlers are mainly used to create a copy of all the visited pages for later processing by a search engine that will index the downloaded pages to provide fast searches.

A web crawler is a computer program that is used to search through millions of websites that are available on the internet according to a search query provided by the user

Crawler are spiders that crawls all the various web pages to provide the necessary web pages as per the user query.

Crawlers are search engine programs that are responsible to read through webpage sources and provide information to search engines.