XSLT (Extensible Stylesheet Language Transformations) is a language for transforming XML documents into other XML documents, HTML, or other formats. It is a key part of XSL (Extensible Stylesheet Language), a family of XML-based languages used for transforming and formatting XML data. XSLT stylesheets define rules for how to process XML elements and attributes, allowing developers to extract, rearrange, and modify data to create different representations. XSLT uses XPath to navigate the XML document structure and apply transformations based on patterns. It is commonly used in web development, data integration, and document processing to convert XML data into more user-friendly or application-specific formats. XSLT processors interpret the stylesheet and apply the transformations to the input XML document, producing the desired output. XSLT is a powerful tool for manipulating XML data and is widely supported across various platforms and programming languages.