Hello, So I am pretty new to GEANT4. I was wondering what this header as it states that it is used for “toring user’s information”. There is no .cc for this file and its almost blank. Is it used for storing event actions such as photons hitting a detector/photodetector?

An example along with an explanation will be really helpful.

Thank you!

G4VUserEventInformation is explained in the Application Developer Guide, and is a base class. It’s used for deriving classes that can be used to attach information about the event, an example of which is provided in example Par02.

For storing/recording data such as you describe the sensitive detector mechanism is better. See also the optical photon examples if that’s the physics being modelled/recorded for your use case.