Final answer:
XML and JSON are useful formats for returning query results because they are interoperable, support data parsing, and provide structured data representation. They are easy to use and understand, and are compatible across different systems, making them ideal for data exchange in web services and APIs.
Step-by-step explanation:
XML (eXtensible Markup Language) and JSON (JavaScript Object Notation) are popular formats for returning query results due to several compelling reasons. XML is a markup language that defines a set of rules for encoding documents in a format which is both human-readable and machine-readable. JSON, on the other hand, is a lightweight data-interchange format that is easy for humans to read and write and easy for machines to parse and generate.
Interoperability is a key advantage of both XML and JSON. They are text-based formats that allow for the exchange of data across different systems, regardless of the specific hardware or software environment. Data Parsing in these formats is simpler as they are widely supported by various programming languages, making it easy to integrate into most platforms. Lastly, Structured Data representation is another benefit. Both XML and JSON provide a structured way to represent complex data, supporting nested and hierarchical objects, which facilitates the organization and manipulation of the data.
These formats are particularly useful when dealing with web services and APIs, where data needs to be transmitted over the Internet and consumed by different client applications. For instance, XML is often used in SOAP (Simple Object Access Protocol) based services, while JSON is commonly associated with REST (Representational State Transfer) APIs.