System variables are settings that control how certain commands work. They can be integer, real, char, bool or RGB color type (i.e. “#FF0000”).
A variable is called “global” when its value doesn’t change when the current project change. These variables are saved and loaded into the QAD.INI file located in the installation folder.
A variable is called “project” when its value change when the current project change. These variables are saved and loaded into <current project name>_QAD.INI file of the current QGIS project folder.