JSON (JavaScript Object Notation) and XML (eXtensible Markup Language) are standardized text formats for storing and exchanging structured data. JSON uses a lightweight syntax based on key-value pairs and arrays, resembling data structures used in programming languages. XML employs tags to define elements and their hierarchical relationships, similar to HTML but for custom data definition. Both serve the core purpose of making data readable for humans and easily processable by machines, acting as common interchange formats. JSON is often simpler and less verbose for representing object-like data.

These formats are widely used for data interchange between different applications and systems. For example, web APIs frequently return data in JSON format to be consumed by client applications like mobile apps or JavaScript in web browsers. Configuration files for software tools are often stored in XML, providing a structured way to define settings. Industries relying heavily on data integration, such as finance for stock feeds or healthcare for patient record exchange, utilize both formats depending on their specific system requirements and legacy integrations.

The main advantage of using JSON or XML is interoperability - they enable diverse systems to share data seamlessly. JSON is generally favored for its conciseness and easy parsing in web contexts, while XML offers stronger validation through schemas (XSD) and better handling of complex document structures. A key limitation is verbosity, particularly for XML, which can increase data size. JSON lacks built-in support for comments or advanced data types like dates. Despite newer formats, JSON and XML remain foundational due to their widespread tooling support and established use cases.