Systems	Geometry
Systems, Variations, Databases	Quickstart —– Native Geant4 —– CAD
Materials	Event Generators
Use Geant4 materials or build your own	GEMC internal generator, available plugins
Digitization	Electromagnetic Fields
Use pre-existing or write your own plugin	Defined Electro-magnetic fields and maps
Physics	Optical Surfaces
Select Geant4 Physics	Define mirrors and surfaces with optical properties
Time Window	GEMC Options
The concept of electronic time window	Options and Steering card
FAQ	Exit Codes