Cauldrons are a symbol of the goddess and a vessel for healing, abundance and transformation. The Cauldron holds feminine energies and represents fertility. It is said to represent a womb for what you put into it will grow into something new.
When using a Cauldron on your altar or for magic you can bring in the elements with it. The Earth is the iron the cauldron is made from, place water inside for water, fire can be applied to underneath and air is all around.