Pravachan is generally used to refer the discourses of a saint or homeless ascetic. The word is mainly used by the adherents of Jainism and Hinduism.
The word pravachan is widely used by Jains. In Jainism, the word śrāvaka is used for the householders. The word has its roots in the word śrāvana, i.e. the one who listens (the discourses of the saints).
The pravachan by Jain saints could be on Jain principles or Jain scriptures (Shastra Pravachan).
During the four-month rainy-season period, when the mendicants must stay in one place, the chief sadhu of every group gives a daily sermon (pravacana, vyakhyana), attended mostly by women and older, retired men, but on special days by most of the lay congregation. During their eight months of travel, the sadhus give sermons whenever requested, most often when they come to a new village or town in their travels.
In Hinduism, the word is used for religious discourse, which are lectures on Hindu scriptures. A Pravachana Pandit becomes a religious and spiritual interpreter of these Scriptures.
Pravachans are usually on a religious theme, usually the life of a saint or a story from one of India's epics. Pravachans sometimes become very emotional. People who listen to Pravachans have become more tolerant of their brethren, a sense of giving and forgiving has been inculcated in them.
In the olden days Pravanchan pundits were often well versed in the Sanskrit language and educated and well trained in Veda Sastras and Vedanta. It is easier to listen to some Pandit or Purohit who is conducting a Pravachan to understand some of the scriptures. Basically the Pandit elaborates on the significance of the sloka or scripture he reads and gives several bhavas and angles to look at a single verse.
Pravachan, Harikatha, Kalakshepa, Upanyasam, Villuppattu are all similar in the sense they are interpretations and story telling on religious theme, yet they have different styles.
South India has a long tradition of religious discourse. Religious scholars such as Oduvars who were knowledgeable in religious scriptures used to render discourses in Temples and monasteries. Villuppttu, in which folk stories were told accompanied by a stringed instrument resembling a bow, was also popular in Tamil Nadu. A form of Kalakshepa, in which the story teller, usually proficient in Carnatic music, interspersed the main story with music, dance and sub-stories, was also prevalent. Harikatha is a composite art form with story telling, poetry, music, drama, dance, and philosophy. Harikatha involves the narration of a story, intermingled with various songs relating to the story.