Global variables

With trials n errors I’m deducing that the only way to have global variables is by putting them inside a global module. Is this correct ?
thanks

Also properties of App and Shared Properties in classes.

Edit, on second thought, those are globally accessible anywhere using App.PropName or MyClass.PropName. For just a singly named, globally accessible property Modules are the tool.

This might help:
http://xojobyexample.com/global-properties-and-methods/