Hey @Robotics (what a cool name 
)
@Palaniyappan explained the use of dictionairy perfectly. I just want to add that there is a workflow in the ReFramework (InitAllSettings.xaml) that creates a dictionairy from values stored in an excel file (usually called Config).
And because this came up before today: you can also store more than one value per key in a dictionairy 
Cheers, Lukas