Typically, each scenario has a number of variables.

As in other programming environments, variables are placeholders for useful information that the scenario needs to keep track of and perhaps modify during its execution. They also indicate the information that will be required by a running instance of the scenario from the end-user in order to configure and start it off, as well as representing the information that will be sent back to be displayed to the user as progress updates or results.

The variables defined in a scenario are shown in the Variables tab. Each variable has a distinct type. If you click on the green box to the left of each variable you can examine its type and other properties.