Web Data Extraction is a type of information retrieval that can automatically extract structured information from unstructured or semi-structured web data sources.
Web scraping is the process of automatically collecting information from the World Wide Web. It is a field with active developments sharing a common goal with the semantic web vision, an ambitious initiative that still requires breakthroughs in text processing, semantic understanding, artificial intelligence and human-computer interactions. Web scraping, instead, favors practical solutions based on existing technologies that are often entirely ad hoc. Therefore, there are different levels of automation that existing web-scraping technologies can provide:
https://en.wikipedia.org/wiki/Web_scraping
