Greater Grail

The Great Grail (大聖杯) is the gateway linked to the Root. It is the magic circle that uses the land managed by the Tohsaka family, a wish machine. The core world, the Cup of Heaven (天の杯).

It is located in the great cave underground of the Ryuudou temple on the Enzou mountain. It consists of a series of seals carved on a radius of above 50 meters of bare rock. Justizia Lizleihi von Einzbern is lying at its center.

Kishua Zelretch Schweinorg was there when it was set up.

The Great Grail is what selects the Masters and invites Heroic Spirits, setting them in the Servant class system. After the three families of the beginning (Einzbern, Matou, Tohsaka), it preferably picks Masters who earnestly want it, although it is possible to have irregulars like Kotomine Kirei in the fourth Holy Grail War, who has no sense of purpose.

It collapses at the end of the fifth War, but the black mud gathers at the bottom.

Source: the dictionary resource at Jonnobi.

The Great Grail is the system, and the Holy Grail is the key to start it up. The Grail collects the souls of the Servants, and the Great Grail uses the energy to open a gateway