Web scraping is a computer technique to extract information from websites using specially coded software programs. Usually, such software programs simulate human exploration of the Web by either implementing the low-level Hypertext Transfer Protocol (HTTP), or embedding certain full-fledged Web browsers, such as the Internet Explorer (IE) or the Mozilla Web browser. Web scraping is closely related to Web indexing, which indexes Web content using Internet robot and is a central technique adopted by most search engines. In contrast, Web scraping focuses more on the transformation of unstructured Web content, typically in HTML format, into structured data that can be stored and analyzed in a central local database or spreadsheet. Web scraping is also related to Web automation, which simulates human Web browsing using computer software. Exemplary uses of Web scraping include online price comparison, weather data monitoring, website change detection, Web research, Web content mashup and Web data integration.