Kumhar or Kumbhar also known as Prajapati, is a caste or community of India, mainly belonging to the Hindu religion. The word "Kumhar" literally means "potter" in Indian languages, pottery being the traditional occupation of the Kumhars.
In Hindu mythology, Kumhars are said to have descended from the Prajapati, the son of the Hindu god Brahma, and hence are referred to as Prajapatis. There are also other stories about them being called Prajapati.In Shiv Purana while Narad Ji listens Shiv Tatva from God Brahma, he calls God Brahmaji as Prajapati so Brahmaji himself is also a Prajapati.
The Kumhar community is found throughout North India in the states of Punjab, Himachal, Western Uttar Pradesh, Haryana, Maharashtra, Gujarat, Rajasthan, Madhya Pradesh Bihar, West Bengal & South India
Traditionally, the Kumhars have been the followers of the Dharmic religions (especially Hinduism), but many of them adopted Islam after the Muslim conquest in the Indian subcontinent.

Mythological origin of kumhars/Prajapatis
The Kumhars derive their name from the Sanskrit word Kumbhakar meaning earthen pot maker. They are also known as Kumbhar(Marathi), Prajapati, Prajapat, Ghumiyar, Ghumar, Kumbhkaar . Today, the Kumhar caste is mainly found in INDIA and Punjab, Bijnor(U.P.) (India). Some Prajapatis/Kumhars trace the origin of their community to the beginning of civilization when the man started using utensils to prepare and eat food. They(Kumhars) consider themselves to be the starters of the world's first industry (pottery).
All sons of Lord Brahma were known to be Prajapatis. There are subcasts that are common in Kumhars and Brahmins. Brahmans are claimed to be offspring of Prajapatis. and Four varnas are developed by Brahmans within themselves but since Kumhars/Prajapatis were there from even before word Brahmins came to existence so they consider themselves different from varnas/Caste system.They say themselves to be different from the caste system and clain them to be higher than all varnas and castes. In Hindu mythology, the Kumhars are the descendants of Lord Prajapati Daksha, son of Lord Brahma. Therefore, they are also known as Prajapati. Daksha Prajapati was a great scholar of Yajur Veda. After being given a prestigious rank by Brahma, he decided to perform a great yagna. He invited rishis, munis, devas and Brahmins to the yagna. On his arrival to the yagna mandap, all of these stood up in respect, except Brahma and Shankar. Prajapati became angry at the apparent disrespect and declared that Shankar will not be allowed to take part in the Yagna. Shankar's gate keeper, Nandi cursed all Brahmins that were there that their entire lineage will live in pity of others and will eat what others will give and will also be Demon-Brahmins and hence many infants of Brahmins will become malicious in kaliyuga. But Kumhars were even then called Prajapatis and so there is no such curse given to this holy honest hardworking high system called Kumhar.Daksha also seem to be given same curse but Shiv purana tells that all Sons of Daksha were told Muki Marga and they become Mukta. This story of kumhars to be infants of only Prajapati Daksha seem to be false. But because prajapatis have surnames such as attris/bhardwaj/gautam/dhadhich etc., so they may be infants who did not study Vedas but worked hard so, those who studied Vedas, become Brahmins and who worked hard become Kumhars.
According to a Hindu mythology, the first Kumbh (earthen pot) was a gift from the Gods. When the gods and the demons were churning the ocean for nectar, there was no vessel to collect the ambrosia. Some other Kumhar myths claim this to be their first creation. Another mythological story says that when Lord Shiva was about to marry Parvati, he realised he had forgotten the water pot integral for the ceremony. Therefore, he gave a part of his skin for clay to Prajapati, the god of creativity, to make a pot. And Parvati gave her blood to decorate the pot. That is when the first kumbh (earthen pot) was created and Prajapati became the first Kumhar (potter). In some temples in Rajasthan (such as Paner) & Himachal Pradesh, only a Kumhar can do the worship not the Brahmins.