The three correct responses that describe a difference between solar wind and a geomagnetic storm are:
1. **Geomagnetic storms are associated with CMEs; solar wind is associated with the constant activity in the sun.**
2. **Solar wind sometimes results in geomagnetic storms; geomagnetic storms do not cause solar wind.**
3. **Geomagnetic storms occur only occasionally; solar wind is constant.**
These points outline the nature of solar wind as a continuous stream of charged particles from the sun, while geomagnetic storms are temporary disturbances in the Earth's magnetic field caused by solar events such as Coronal Mass Ejections (CMEs).