The deities of Hinduism have evolved from the Vedic era (2nd millennium BC) through the medieval era (1st millennium AD), regionally within Nepal, India and in southeast Asia, and across Hinduism's diverse traditions. The Hindu deity concept varies from a personal god as in Yoga school of Hindu philosophy, to 33 Vedic deities, to hundreds of Puranics of Hinduism. Illustrations of major deities include Vishnu, Sri (Lakshmi), Shiva, Sati, Brahma and Saraswati. These deities have distinct and complex personalities, yet are often viewed as aspects of the same Ultimate Reality called Brahman. [note 2] From ancient times, the idea of equivalence has been cherished for all Hindus, in its texts and in early 1st millennium sculpture with concepts such as Harihara (half Shiva, half Vishnu), Ardhanārīshvara (half Shiva, half Parvati), with myths and temples that feature them together, declaring they are the same. Major deities have inspired their own Hindu traditions, such as Vaishnavism, Shaivism and Shaktism, but with shared mythology, ritual grammar, theosophy, axiology and polycentrism. Some Hindu traditions such as Smartism from mid 1st millennium AD, have included multiple major deities as henotheistic manifestations of Saguna Brahman, and as a means to realizing Nirguna Brahman.