Differences Between Web Crawling and Web Scraping
When collecting data from the web, crawling (Web Crawling) and scraping (Web Scraping) are often used interchangeably. However, strictly speaking, these two terms have different meanings.
In this lesson, we will explore the key differences between web crawling and web scraping.
Crawling
Web crawling refers to the process of exploring the link structure of web pages and comprehensively collecting and storing data by visiting various pages of a website.
For example, collecting information about multiple products from an online store or starting from the homepage of a news website to collect the latest news articles and storing them in a database falls under crawling.
How Does Crawling Work?
Crawling utilizes data collection software and bots known as web crawlers (or spiders). Crawlers begin at one page and follow all the hyperlinks on that page to collect data.
How is Crawling Used?
Crawling is used by search engines like Google to index web pages. Indexing involves analyzing the content of web pages and systematically organizing it for storage in a database.
This allows search engines to quickly provide users with highly relevant search results.
Scraping
Scraping refers to extracting specific information from a particular web page.
For instance, analyzing a product detail page in an online store to extract the product's price, description, and images is considered scraping.
How Does Scraping Work?
Scraping generally involves analyzing the HTML content of a web page to selectively extract the required data.
How is Scraping Used?
Unlike crawling, which collects entire website data by following connected links, scraping extracts only the required information from a specific web page. For example, scraping can be used to extract the title, author, and publication date from a specific news article.
To Summarize the Differences:
Crawling refers to the process of following the entire structure and links of a website to collect and store data, while scraping means selectively extracting the required information from a specific web page.
Crawling is used by search engines to index web pages using crawlers (or spiders), whereas scraping involves analyzing the HTML content of a specific URL to extract the required information.
As in the previous lesson, collecting data from a specific URL is, strictly speaking, considered scraping.
However, since crawling is a more general and comprehensive term than scraping, we will primarily use the term web crawling in these lessons.