Web crawling and web scraping are two distinct processes used for extracting information from websites.

Web crawling involves systematically traversing the web by following links to reach multiple pages and collecting information to build search indexes for search engines. It starts from a list of seed URLs and provides a comprehensive view of a site’s structure and the connections between its pages.

On the other hand, web scraping is focused on extracting specific information from a web page. It is targeted at particular websites for extracting specific data, such as price comparison. Unlike web crawling, web scraping may not adhere to robots.txt rules, allowing it to submit forms with data and execute JavaScript if necessary. It disregards elements common to all pages, enabling the extraction of targeted data.

While web scraping can be performed without web crawling, crawling often involves some level of scraping to extract URLs. Both processes are essential for data extraction, each serving unique purposes and employing distinct methodologies.

What is Web Crawling?

Web crawling refers to the process of finding and fetching web links in order to collect information and build search indexes, providing a broad perspective on a site’s structure and connections between pages.

It involves following links from a list of seed URLs and estimates the time needed to visit all interested pages.

Web crawling helps in understanding the structure and links of a website, allowing for a comprehensive view of specific parts of the site. It is an important process for search engines to gather information and index web pages.

Unlike web scraping, web crawling is not targeted at specific websites or data extraction. Rather, it focuses on exploring and mapping the overall structure of a website.

What is Web Scraping?

The process of extracting information from a webpage involves targeting specific websites for specific data, such as price comparison, and can be done without the need for crawling.

Web scraping is the essence of data extraction, focusing on processing a web document and extracting relevant information from it.

Unlike web crawling, which provides a broad perspective on a site’s structure and connections between pages, web scraping covers specific parts of a website.

It allows for targeted extraction of specific data while ignoring extraneous information like comments or breadcrumbs.

Web scraping involves techniques like submitting forms with data and executing JavaScript if required.

It may not adhere to robots.txt rules and can identify itself as a browser to access the desired information.

Comparison

Comparing the processes of web scraping and web crawling reveals distinct purposes and processes involved.

Web scraping is the process of extracting information from a web page, targeting specific websites for specific data. It involves processing a web document and extracting relevant information while ignoring extraneous parts like navigation and ads. Web scraping allows for targeted extraction of specific data, providing a comprehensive view of specific parts of a website.

On the other hand, web crawling is the process of finding and fetching web links. It follows links to reach multiple pages, collects information to build search indexes, and provides a broad perspective on a site’s structure and connections between pages.

While web scraping can be done without web crawling, crawling requires some level of scraping to extract URLs. Both processes are important for data extraction, but they serve different purposes and require different approaches.