RDFa, or Resource Description Framework in Attributes, is a markup language used to add structured data to web pages. It allows website creators to embed metadata, such as descriptions and relationships, directly into HTML code, making it easier for search engines and other applications to understand and process the content. This enables websites to provide more relevant and accurate results to users, as well as improve their overall accessibility and visibility on the web. RDFa is a powerful tool for creating semantic web content and enhancing the user experience, making it an essential component of modern web development.