JSON is an extremely popular format for storing and manipulating data. It stands for JavaScript Object Notation.

One of its advantages is that it is easy for humans to read and write and for machines to parse and generate.

Here is a simple example of data structured in JSON format:

{"user": {
  "id": "309",
  "fullname": "Anna Loud",
  "firstname": "Anna",
  "preferences": {
    "food": [
      {"ingredient": "Potato", "appreciation": "1", "level": "35"},
      {"ingredient": "Lettuce", "appreciation": "1", "level": "12"},
      {"ingredient": "Chocolate", "appreciation": "0"}
    "music": [
      {"genre": "Classical", "appreciation": "1", "level": "35"},
      {"genre": "Rock", "appreciation": "1", "level": "12"},
      {"genre": "New Age",  "appreciation": "0"}
    "city": "Rotterdam"