JSON, or JavaScript Object Notation, is a lightweight data interchange format that is easy for humans to read and write. It is commonly used to transmit data between a server and a web application, making it a popular choice in web development. JSON structures data in key-value pairs, similar to how objects are defined in JavaScript. One of the main advantages of JSON is its simplicity and flexibility. It can represent complex data structures, including arrays and nested objects, while remaining easy to parse and generate. Many programming languages, including Python, Java, and Ruby, provide built-in support for working with JSON, making it a versatile choice for data exchange.