The document explains web scraping as a method for extracting large volumes of data from websites into local files, emphasizing its utility for various applications. It details the three main steps of web scraping: getting content, parsing the response, and preserving the data, while outlining tools and libraries available like BeautifulSoup and Scrapy. Additionally, it addresses challenges, ethical considerations, and offers examples of practical applications, stressing the importance of conforming to a site's terms of use.