JSON stands for JavaScript Object Notation, and it 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 often used for transmitting data between a client and a server in web applications.

JSON data is represented as key-value pairs, where the keys are strings and the values can be any valid JSON data type, including strings, numbers, booleans, null values, arrays, and other JSON objects. Here's an example of a simple JSON object:

{
 "name": "John",
 "age": 30,
 "is_student": true,
 "hobbies": ["reading", "writing", "coding"],
 "address": {
   "street": "123 Main St",
   "city": "New York",
   "state": "NY",
   "zip": "10001"
 }
}

In this example, the keys are `"name"`, `"age"`, `"is_student"`, `"hobbies"`, and `"address"`, and the values are a string, a number, a boolean, an array, and an object, respectively.

JSON is often used in web development because it is easy to parse and generate using JavaScript, which is the primary language used for client-side scripting in web browsers. Many web APIs also use JSON as their data interchange format, making it easy for developers to consume and process data from these APIs.

In summary, JSON 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 commonly used for transmitting data between a client and a server in web applications, and is represented as key-value pairs where the keys are strings and the values can be any valid JSON data type.