JSON, short for JavaScript Object Notation, is a lightweight data interchange format that is easy for humans to read and write, and easy for machines to parse and generate. It is based on a subset of the JavaScript Programming Language, Standard ECMA-262 3rd Edition - December 1999. JSON is often used to transmit data between a server and a web application, as an alternative to XML.

JSON data is represented as key-value pairs, similar to how objects are represented in JavaScript. The key is always a string, enclosed in double quotes, followed by a colon, and then the value. The value can be a string, number, boolean, array, object, or null.

Here's an example of a JSON object:

{
  "name": "John Doe",
  "age": 25,
  "isStudent": true,
  "hobbies": ["reading", "coding", "gaming"],
  "address": {
    "street": "123 Main St",
    "city": "New York",
    "country": "USA"
  },
  "isNull": null
}

In this example, the JSON object represents a person named John Doe. It includes properties such as name, age, isStudent, hobbies, address, and isNull. The hobbies property is an array, and the address property is another JSON object nested within the main object.

JSON is widely used in web development because of its simplicity and compatibility with various programming languages. It is supported by most modern browsers and has become the de facto standard for data interchange on the web.

For more information and detailed specifications, you can refer to the official JSON website: https://www.json.org/.