The term sutra means thread. The first among the sutra literature is Srauta Sutra. It deals with Vedic sacrifices. Sulva Sutra prescribes various kinds of measurements for the construction of sacrificial altars. The Dharma Sutra deals with social duties. The Sutras have been divided into four parts

1. Srauta Sutra
2. Kalpa Sutra
3. Griha Sutra
4. Sulva Sutra