In short, web scraping is the extraction (= 'scraping') of data from the aforementioned websites.
The technique uses specific software to extract this information (often personal data) and then, where necessary, store and analyse it. The Internet often contains a great deal of data that may be of interest to one or other party.
It takes too much time to process this information manually, and it changes regularly.
Scraping therefore makes it possible to process personal data on a large scale (at a later date) using a relatively automated process.
Scraping is limited by data protection rules and must be handled with care.