What is JSON? For what is used for?

JSON (JavaScript Object Notation) is a data storage and communication format based on key-value pair of JavaScript object literals. It is a lightweight text-based open standard designed for human-readable data interchange which is derived from the JavaScript programming language for representing simple data structures and associative arrays, called objects.

In JSON

• all property names are surrounded by double quotes.
• values are restricted to simple data: no function calls, variables, comments, or computations.

JSON is used for communication between javascript and serverside technologies.