The Outputs step allows to specify the resulting parameters of the stack-affected resources that will be shared with the user. This info is added to the Output section of the Maestro Stack execution report that is sent to the user's email after the stack execution finishes (successfully or not). You can specify the output parameters for all the commands used in your stack flow, both primary and additional. Each command has a default set of output parameters, but you can manage or delete them if necessary.
For more details on the Outputs organization in a Maestro Stack template, please, see our Maestro Stacks Guide, Section "2.1.3. The Outputs block"