It's typically used to denote a person's former name, e.g. "Virginia Woolf, née Stephens" or "Elliott Gould, né Goldstein". The feminine form is much commoner than the masculine since it is culturally less common a man to change his surname than for a woman to change hers, mostly by adopting her husband's surname upon marriage.
Né, in French, is the past participle and past participial adjective of the verb naître, meaning "to be born". In its feminine form, it is inflected with feminine -e, as per standard French grammar. This rule is usually followed when this is loaned to English.