Define the User type to deserialize the JSON into. There is no need to mark a type or the members of that type with special attributes to opt into the deserialization—all public members are included automatically in the data contract.
https://msdn.microsoft.com/en-us/library/cc197957(v=vs.95).aspx
JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write. It is 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.
http://json.org/
JSON is a very simple text format based on JavaScript's object notation. 1  Objects. Objects begin and end with curly braces 2  ({}). Object members. Members consist of strings and values, separated by colon (:). Members are separated by commas.  Arrays. Arrays begin and end with braces and contain values.
https://developer.yahoo.com/javascript/json.html
Using JSON (JavaScript Object Notation) with Yahoo! Web Services. JSON (JavaScript Object Notation) is a lightweight data format based on the object notation of the JavaScript language. It does not require JavaScript to read or write; it is easy to parse by any language and libraries and tools exist in many languages to handle JSON.
https://developer.yahoo.com/javascript/json.html
In JSON, they take on these forms: An object is an unordered set of name/value pairs. An object begins with { (left brace) and ends with } (right brace). Each name is followed by : (colon) and the name/value pairs are separated by , (comma). An array is an ordered collection of values.
http://json.org/
Using JSON and callbacks, you can place the Yahoo! Web Service request inside a <script> tag, and operate on the results with a function elsewhere in the JavaScript code on the page. Using this mechanism, the JSON output from the Yahoo! Web Services request is loaded when the enclosing web page is loaded.
https://developer.yahoo.com/javascript/json.html
Working with JSON Data. HTTP-based Web services frequently use JavaScript Object Notation (JSON) messages to return data back to the client. JSON objects can easily be instantiated in JavaScript, without parsing logic, which makes it a convenient format for messages in Web applications.
https://msdn.microsoft.com/en-us/library/cc197957(v=vs.95).aspx
Working with JSON Data. Silverlight. HTTP-based Web services frequently use JavaScript Object Notation (JSON) messages to return data back to the client. JSON objects can easily be instantiated in JavaScript, without parsing logic, which makes it a convenient format for messages in Web applications.
https://msdn.microsoft.com/en-us/library/cc197957(v=vs.95).aspx
JSON is built on two structures: 1  A collection of name/value pairs. In various languages, this is realized as an object, record, struct, dictionary, hash table, keyed list, or associative array.  An ordered list of values. In most languages, this is realized as an array, vector, list, or sequence.
http://json.org/
Using JsonObject with LINQ allows us to easily deal with complex JSON objects. Assume, for example, that the following JSON is contained in the responseStream object of type Stream. To retrieve all people who are members, use the following LINQ query over a JsonArray object.
https://msdn.microsoft.com/en-us/library/cc197957(v=vs.95).aspx
what is a json file?
A json file is a lightweight data format based on the object notation of the JavaScript language.   A JavaScript Object Notation file is a lightweight data format based on the object notation of the JavaScript language.