JSON (JavaScript Object Notation) is a lightweight, human-readable data-interchange format. It is widely used for transmitting data between a server and web applications, as well as for configuration files and data storage. JSON is based on a subset of the JavaScript programming language, but it is language-independent and can be parsed and generated by many programming languages. Its simple structure, consisting of key-value pairs and arrays, makes it easy to understand and work with. JSON files are typically used to represent structured data, such as objects, arrays, and primitive data types like strings, numbers, booleans, and null. The format's simplicity and ubiquity have made it a cornerstone of modern web development and data exchange, replacing older formats like XML in many applications. JSON's ability to represent complex data structures in a clear and concise manner contributes to its popularity and widespread adoption across various platforms and technologies. It is often used in APIs, configuration files, and data serialization.