A gotra is the lineage or clan assigned to a Hindu at birth. In most cases, the system is patrilineal and the gotra assigned is the gotra of the person`s father. The literal meaning of Gotra is "cow-pen" or "cow-shed" in archaic rigvedic Sanskrit.

Gotra is the Sanskrit term for a much older system of tribal clans. The Vedic people for the identification of the lineages initially used the Sanskrit word "Gotra". Generally, these lineages mean patrilineal descent from the mythical sages or rishis in Brahmins, warriors and administrators in Kshatriyas and ancestors in Vaisyas.

A Gotra relates directly to the original seven or eight Rishis of the Vedas. The concept of Gotra has always been associated with the Brahmins. The Gotra has always been only a Brahmin lineage that descends from seven or eight rishis associated with the seven or eight stars of the Great Bear constellation as according to original Hindu Vedic system. The seven rishis were Gautama, Bhardwaja, Vishwamitra, Jamadagni, Vasistha, Kashyapa and Atri.

The word "Gotra" means "ray." In Brahmin tradition, it is the duty of the Brahmin to keep his particular ray alive by doing daily rituals that he may transmit the power of that ray to others for the benefit of mankind. When the "ray" is extinguished, so is that particular beneficial magical stream dead to the human race and that power lost to mankind forever.

Today, the concept of `Gotra` is not anymore restricted to the Brahmin lineage. Therefore, today, other terms are considered synonymous with gotra and the distinct meaning of the word and the esoteric connotations are lost to many even among the Brahmin community. A common mistake is to consider Gotra to be synonymous with cult or Kula. Kula has nothing to do with lineage or caste. In fact, it is possible to change one`s Kula, based on his faith or ista devtha unlike the Gotra.

Types of Gotras:
As mentioned above, Gotra stands for lineage or clan assigned to a Hindu at birth. Hence it is believed that, People belonging to the same gotra also belong to the same caste in the Hindu social system. But in matrilineal Tulu/Malayalee speakers the lineages are the same across the castes.

Some of the common lineages are as follows:

Brahmin Gotras

Vysya Gotras

Dhangar Gotras

Jats

Tulu/Malyalees

Importance of Gotra during marriage
It is common practice in Hindu marriage to enquire about the Kula-Gotra meaning Cult-Clan of the bride and bridegroom before approving the marriage. While marriage within the kula is allowed and even preferred, marriage within the Gotra is not allowed. This is because, marriages within the gotra ("sagotra" marriages) are banned under the rule of exogamy in the traditional matrimonial system. People within the gotra are regarded as kin and marrying such a person would be thought of as incest. In some communities, where gotra membership passed from father to children, marriages were allowed between uncle and niece but in the martilineal societies this is strictly banned.

North Indian Hindu society not only follows rules of gotra for marriages, but also has many regulations which go beyond the basic definition of gotra.