Used to register variables defined in a module when it is invoked in a task
The registered data is stored in JSON format
The value of the variables set using the register clause is always a dictionary, but the specific keys of the dictionary are different, depending on the module that was invoked.
Every module will have a different dictionary of variables that it will try to gather from the host.
Below example shows the three dictionary values that were registered when using backup parameter in ios_config module.