The first required characteristic of the Brahmin caste is that there be inherited, genetic blood-relation, as Brahminism is a subset of a tribal (hereditary) lineage. Brahmins originated in the northern regions of the lands now know as India, Pakistan and Afghanistan, an area which is described in the Vedas as having a powerful river called Sarasvati in the Indus Valley and that dried up around 1900 before the common era (BCE).
The second requirement is that Brahmin practice Brahminism, one of the hundreds of forms of Hindu religion. Therefore, Brahmins have a distinct and specialized culture with distinct and specialized religious practices, traditions, principles and other practices. Brahminism is also called Sanatana Dharma or Vedic religion. The Vedas is central to Brahminism, as it is to most other forms of Hinduism; it is the most ancient text and respected as human heritage. The Vedas has been protected by UNESCO as part of the world heritage.
The third requirement is religious belief. To Brahmin, both orthodox and heterodox, the Vedas are divine, inspired texts that are apaurusheyam, meaning "not man made." They are therefore revealed truths, not learned truths, and have eternal validity and relevance to humankind. This quality defines the Vedas as Srutis, meaning "that which have been heard."
The fourth requirement is religious practice. Brahmins' daily religious practices include sandhyavandana, which are prayers to the Sun God and Gayatri; prayer to the personal god ishtadaiva or ilavelpu; the practice of yoga; the rejection of violence; the dietary practice of vegetarianism. Added to these and other daily rituals, in a Brahmin life composed of ritual, are special occasion rituals, such as a special marriage ritual and a baby's first feeding ritual, along with many others.