It is written in short aphoristic style so that they could be easily memorized. Kalpa is considered as one of the six parts of the Vedangas. As they are regarded to be of human origin, they are considered ‘Smriti’ as distinct from the earlier Vedic literature, which is ‘Shruti’. Most Kalpa Sutras texts have experienced interpolation, changes and consequent corruption over their history and Apasthamba Kalpa Sutra ancillary to the Yajur Veda may be the best preserved text in this genre.
Etymology of Kalpa Sutras
Kalpa is a Sanskrit word that means "proper, fit, competent, sacred precept", and also refers to one of the six Vedanga fields of study. This field of study is focussed on procedures and ceremonies associated with Vedic ritual practice. The Vedangas are first mentioned in the Mundaka Upanishad as topics to be observed by students of the Vedas. Later, they developed into independent disciplines, each with its own corpus of Sutras.
Division of Kalpa Sutras
Kalpa is the method of ritual. A Kalpa Sutra is divided into four parts. They are:
1. Srauta Sutra - Srauta Sutra deals with sacrificial rituals.
2. Grihya Sutra - Grihya Sutras deal with domestic rites of passage.
3. Dharma Sutra - Dharma Sutra deals with morals, ethics, law and politics.
4. Sulba Sutras - Sulba Sutra deals with the altar geometry that is notably a part of the Srauta Sutras.
In fact, these texts can be considered as separate compositions as each of them have been compiled by different sages. These texts date back to 500 B.C.
Kalpa Sutras are also found in other Indian traditions such as Jainism.