The sanctioned Internet media category for JSON is application/JSON. The JSON filename extension is .json. JSON expanded because of instantaneous server-to-browser communiqué minus browser plugins like Flash or Java applets, which were the leading techniques in the early 2000s. Douglas Crockford first started and popularized the JSON format. JSON lets us overpower the cross-domain issues, as it employs a call-back function to return the JSON data back to the domain.