TL;DR
Web crawling is discovery: following links to find and traverse pages across a site. Web scraping is extraction: pulling specific data out of those pages. Crawling answers which URLs exist, scraping answers what is on them. Most real projects combine both, crawling to find pages and scraping to collect their data.
Two Different Jobs
The confusion comes from the fact that most tools do both, but they are separate operations.
Crawling is about movement. A crawler starts at a seed, reads the links on each page, and follows them to discover more pages. Its output is a set of URLs and the structure connecting them. Search engines crawl to build an index of what exists.
Scraping is about content. A scraper takes a specific page and extracts structured fields from it: a price, a title, a table, a set of reviews. Its output is data, not URLs.
A Concrete Example
Say you want every product price on a store:
- Crawl the category pages to discover all product URLs.
- Scrape each product URL to extract name, price, and stock.
Step one is crawling (finding the pages); step two is scraping (reading them). Neither alone gets the job done: crawling without scraping gives you a list of links with no data, scraping without crawling means you already need the URL list.
When You Need Only One
- Crawling only. Building a sitemap, checking for broken links, or mapping a site's structure needs traversal but no extraction.
- Scraping only. If you already have the exact URLs (from a feed, an API, or a known pattern), you skip discovery and extract directly.
Key Takeaways
- Crawling discovers and traverses URLs; scraping extracts data from pages.
- Crawling outputs links, scraping outputs structured data.
- Most jobs crawl to find pages, then scrape to collect their contents.
How ScrapeGraphAI Handles This
ScrapeGraphAI separates the two cleanly: the crawl endpoint discovers and traverses pages, while scrape and extract pull content and structured JSON from a page. Crawl combines them, extracting from each page it discovers.