XML (Extensible Markup Language) is a flexible, text-based format used for storing, organizing, and exchanging structured data across different systems. Developed by the W3C (World Wide Web Consortium) in 1998, XML is both human-readable and machine-readable, making it suitable for data interchange between applications built on different platforms and programming languages. XML uses tags and attributes to define elements and relationships within the data, similar to HTML, but unlike HTML, XML focuses on describing the data’s structure rather than its presentation. Its extensibility allows developers to create custom tags, making it highly adaptable for specific use cases.
XML is widely used in web services, configuration files, and data storage systems, particularly where hierarchical data structures are required. It supports schemas like DTD (Document Type Definition) and XSD (XML Schema Definition) to enforce rules about the data structure, ensuring validation and consistency. XML also integrates with XPath and XSLT to query and transform data, enabling flexible data processing. Although newer formats like JSON have become more popular for modern web applications due to their simplicity and efficiency, XML remains important in industries like finance, healthcare, and enterprise systems, where data integrity and complex data modeling are critical.