Her name, according to the prevailing etymology, means Mother Earth in Greek language, and that's exactly what she is. A peaceful goddess of agriculture, fertility, harvest and grains.
The sacred symbols of Demeter are the wheat, the barley, the bee and in extension, the honey.
Going further to Ancient Greek Philosophy, we find that except the obvious meaning of agriculture there is a deeper view that the earth is the visualisation of the human's soul. If that is the Truth, please imagine what agriculture teaches us about our soul and our personal growth.