application/json. The JSON filename extension is
.json. The specific section of the standard that JSON is part of is ECMA-262. These are well documented and widely-followed standards, which should give you a comfort factor when using a new technology.
Of course, no one should use a technology just because some really big name players use it. So why should you use JSON? Most definitions of JSON say that it’s “lightweight.” What does that mean? Compared to XML, the ratio of markup to content with JSON is far lower. This means it’s smaller, less complex to generate or retrieve and easier to read. That translates into faster load times for web pages and the ability to send more data, more quickly than with other data formats.
None of the above is meant to discredit XML in any way, but to show the strengths and uses of JSON. As with many things, this is a horses for courses discussion. As a matter of fact, another plus for JSON is that JSON and XML are not mutually exclusive. JSON plays well with other tools – and you may find opportunities to use the strengths of each to build your applications. Speaking of playing well together, another excellent pairing is JSON and JQuery.
Another use of JSON is to store complex data structures in databases. An entire object can be stored in a single field of the database table. Using JSON, you can build a more advanced non-relational data-store. In some respects this is similar to the use of .ini files to hold data structures for things like configuration information, rather than more complex mechanisms like a registry. This comes back to its use of name/value pairs, which are simple and efficient.