What was the significance of gotras in Brahmanical practice?

They linked individuals to Vedic seers as descendants.

From around c. 1000 BCE onwards, one of the Brahmanical practices was the classification of people, especially Brahmanas, based on their "gotras." Each gotra was named after a Vedic seer, and individuals belonging to the same gotra were considered descendants of that seer. Notably, two significant rules concerning gotras were in place: First, women were expected to relinquish their father's gotra and adopt their husband's gotra after marriage. Second, individuals belonging to the same gotra were forbidden from marrying each other.