Jyoti Kalash is a combination of earthen pot (usually a pitcher) and a big lamp (known as Diya) above it. The earthen pot is covered with a lid and the lamp is placed on top of it.
Jyoti Kalash is considered sacred and divine as Jyoti Kalash symbolically represents Goddess Durga during Navratri. The divine lamp is continuously lit for nine days and fuelled with pure Ghee. The fire of lamp symbolizes the divine presence of Mata Durga on the earth during nine days of Navratri.
Jyoti Kalash is community ritual and usually performed in big halls surrounding some big temple. Jyoti Kalash(s) are lit by devotees for nine days which are supervised by volunteers. On the ninth and final day, the procession of Jyoti Kalash is taken out and it is immersed in the river or some other water bodies. Usually Jyoti Kalash is kept inside a temple but many devotees keep it at home also.
The ritual of Jyoti Kalash is more popular during Sharad Navratri and mainly observed in North Indian states like Chhattisgarh, Rajasthan, Uttar Pradesh and Madhya Pradesh.