Grihya Sutras are the Kalpasutras dealing with the domestic ceremonies and sacrifices of daily life. The Kalpasutras themselves arose out of the need to compile the rules for the sacrificial ritual in a shorter, more manageable and connected form for the practical purposes of the priests. Apart from the Grihya Sutras, the Kalpasastras dealing with the Srauta sacrifices taught in the Brahmanas are called Srautasutras. The composition and importance of the Grihya Sutras are discussed below.

Content of Grihya Sutras
The contents of the Grihya Sutras are manifold and also rather interesting. They contain directions for all usages, ceremonies and sacrifices by virtue which the life of a person receives a higher sanctity. This Samskara is outlined for a person right from the moment when he is conceived in the womb, till the hour of his death and still further through the death-ceremonies and the cult of the soul. Thus there can be found in these works a large number of genuine popular customs and usages treated in detail, which refer to conception, birth, the mother and the new-born child, the name-giving, the first outing and the first feeding of the child. There are exact directions for the shaving of the boy's head, the introduction of the pupil to the teacher (Upanayana or "initiation of the pupil"), the mode of life of the Brahmacharin or Veda-student and the dismissal of the pupil from the service of the teacher. The customs to be followed during the time of wooing, betrothal and marriage are presented in an especially detailed manner.

In the Grihya Sutras, the "five great sacrifices" already mentioned in the Shatapatha Brahmana, are minutely described. They are called "great sacrifices" because their performance is among the most important religious duties of every head of a household, although in reality they consist only of small gifts and a few simple ceremonies. These are the daily sacrifices to the gods, demons and fathers, which need only consist of the pious laying of a bag of wood upon the sacred fire of the hearth, a few scraps of food, a libation of water, further, hospitality to a guest (designated as "sacrifice to man") and fifthly, the daily reading of a section of the Veda, considered as sacrifice to the Brahman. The simple evening and morning offerings, the new and full moon sacrifices, and the annual festivals connected with sacrifices are also presented in the Grhyasutras.

In addition, such customs and ceremonies are described as refer to house-building, cattle-breeding and farming, also those of the magic rites which are to serve for averting diseases and unpropitious omens, as also exorcisms and rites for love magic and such like. Finally the Grhyasutras deal also with the funeral customs and the ancestral sacrifice (Sraddhas), which, however, assumed such importance that they were soon treated with their most minute details, in special texts (Sraddha Kalpas).

Importance of Grihya Sutras
Thus, these Grihya Sutras are valuable texts as they provide a great insight into the life of the ancient Indians. These are almost like the reports of eye-witnesses on the daily life of the ancient Indians, in the form of rules and precepts in these apparently insignificant Sutra texts. They are, as it were, the "Folklore Journals" of ancient India. It is true that they describe the life of the ancient Indian father of the family only from the religious side, but as religion permeated the whole existence of the ancient Indians to such an extent that actually nothing could take place without an attendant religious ceremony, they are for the ethnologist most invaluable sources for the popular customs and usages of that ancient period. The numerous parallels in the manners and customs of other Indo-European peoples, which have been discovered long ago, with the usages described in the Grhyasutras, make these documents all the more important. In particular, the comparison of the Greek, Roman, Teutonic and Slavonic marriage customs with the rules contained in the Grihya Sutras has shown that the relationship of the Indo-European peoples is not limited to language, but that these peoples, related in language, have also preserved common features from prehistoric times in their manners and customs.