Demeter was one of the original six Olympians, the daughters and sons of Cronos and Rhea. She did not spend all her time on Mount. Olympus, but instead wandered the fields in her role as the goddess of grain and harvest. Though she was away from Mount Olympus, she was still very involved with the happenings of the other Olympic gods, unlike her brother Hades.
Demeter was a very popular goddess in Greece. The harvest was very central to the early Greeks, who held her in high esteem. She was portrayed as being kind and generous. This view came from the need for her to give her blessing of fertility on the earth for all to benefit.