It is associated with the Celtic goddess Cerridwen. The dead were brought back to life when placed in her cauldron.
CHALICE -- The chalice is associated with the element water and is used to represent it on the altar. It is used for rituals as well. They can be ornate or as simple as a mug. It is is used with the athame to perform the Great Rite, which is the symbolic joining of the God and Goddess.
CHARM -- An object charged with energy for a specific task.
CIRCLE -- This is the the place that ritual magic takes place. It is formed through personal energy and visualization.
CRONE -- The third aspect of the Goddess. She is the is symbolized by the waning crescent moon. She is part of winter when the land is cold. She is the old wise woman. She is the end of the cycle before rebirth.
Disclaimer: None of these pictures belong to me. I found them on Google.