In ancient and medieval India, the dvijas (‘twice-born’ ones), especially the brāhmaṇa householders, were expected to maintain the śrauta or the Vedic fires in which they had to offer Agnihotra everyday. Those who had thus established duly consecrated sacred fires were called ‘āhitāgnis.’ However, even those who had not done so, had to offer Agnihotra twice everyday. This was done in the fire kindled at the time of marriage and maintained thereafter. This fire was known by several names: aupasada, aupāsana, āvasathya, vaivāhika, smārta, gṛhya or śālā-agni.
See AGNIHOTRA for details.