Java SE does not have JSON support in the standard library. So, you can use any of the following - Jackson, GSON or JSON.simple (ranked popularity-wise). JSONObject is a class provided by JSON.simple library.
They are just different libraries to handle JSON in Java. What is there to "get"? It's like asking "What is the exact difference between a Ford car and a Dodge car?" Both are cars and you choose the one that suits you best.
Similarly, choose the JSON library that seems to suit your needs best.
