XML-based protocols are communication standards that use XML (eXtensible Markup Language) to structure data. These protocols enable different systems to exchange information in a format that is both human-readable and machine-readable. They are widely used in web services, allowing applications to interact over the internet seamlessly. Common examples of XML-based protocols include SOAP (Simple Object Access Protocol) and REST (Representational State Transfer). These protocols facilitate data exchange between diverse platforms and programming languages, making them essential for modern software development and integration. Their flexibility and extensibility contribute to their popularity in various industries.