In the context of Hindu society, a Gotra is a lineage or clan system. It refers to a group of people who are believed to have descended in an unbroken male line from a common male ancestor, who was often a revered ancient sage or \textit{Rishi}. 
The primary importance of Gotra is in the regulation of marriage through the rule of Gotra Exogamy. 
Key Points: 
    
 Prohibition of Marriage: The rule of Gotra exogamy strictly prohibits marriage between a man and a woman who belong to the same Gotra. They are considered to be siblings, and such a union would be regarded as incestuous. 
    
 Maintaining Lineage: This practice is intended to maintain the purity of the lineage and is based on traditional beliefs about genetics and social order. 
    
 Social Regulation: While its traditional rigidity has lessened in modern urban contexts, the concept of Gotra remains a significant factor in matrimonial alliances, especially in arranged marriages in many parts of India.