Which variable field is optional when creating a variable, in UiPath Studio?

In UiPath Studio, when creating a variable, the "Default" field is optional. The "Default" field is where you can assign an initial value to the variable, which it will hold until changed during the execution of the workflow. The "Variable type" must be specified to determine what kind of data the variable will hold. The "Name" is required to reference the variable within the workflow, and the "Scope" determines where the variable can be accessed from within the project.