Shrauta means belonging to “shruti” (that which is heard). They are based on the four Vedas (called shrutis)- Rig Veda, Yajur Veda, Sama Veda and Atharva Veda. The ceremonial ritual of an elaborate homa (ritual where offerings are made into the fire) by several priests characterizes a Shrauta assembly. This was also known as Yajna or a Vedic fire sacrifice that includes copious offerings of honey, milk, clarified butter, yogurt, rice and barley. In some cases, animal sacrifice is also known to have formed part of this ritual, though this later came to be frowned upon by the Brahmans. The priests created workaround of moulding animal shapes from dough for the sacrificial fire, in accordance with their sampradaya or tradition.
The nature of the offering does not seem to be important for a Shrauta ritual. The offering can be as small as plain milk, vegetables or pulses, or even as large as a cow. A Shrauta ritual could be either an agnihotra (purifying the atmosphere through a specially prepared fire) or agnicayana (erecting a special bird shaped structure for an elaborate 12 day yajna). As the arrangements were elaborate and expensive, only the rich, royal and noble citizens had the wherewithal to conduct the Shrauta rituals.
It was not uncommon for the ladies of the house to chant related mantras (religious chants) while the Yajna was in progress.
The practice of Shrauta saw a decline with the advent and popularity of the Upanishads by the 13th century CE. As opposed to elaborate ceremonies, the affluent began giving away domesticated animals and land, erecting public facilities, feeding the poor and donating gold and jewels to temples, to signify their God-realization.
The Shrauta-sutra, Grihya-sutra and Dharma-sutra are collectively known as Kalpa-sutra.