Thank you in advance.
For instance, you can use it for operations which would not directly be possible using the regular actions and then use the result in your process.
While handling JSON Objects, you can convert the JSON output into custom object by using action called "Convert Json to Custom Object". Accordingly you can work on same object.
If you're trying to use any specific operation with this action, please let us know the details so that we may help you out.
You may refer to the following articles for some samples:
Hope this helps...