The Vedas (Sanskrit: , "knowledge") are a large body of texts originating in ancient India. Composed in Vedic Sanskrit, the texts constitute the oldest layer of Sanskrit literature and the oldest scriptures of Hinduism. Hindus consider the Vedas to be apauruṣeya, which means "not of a man, superhuman" and "impersonal, authorless". Vedas are also called ("what is heard") literature, distinguishing them from other religious texts, which are called ("what is remembered"). The Veda, for orthodox Indian theologians, are considered as revelations, some way or other the work of the Deity. In the Hindu Epic the Mahabharata, the creation of Vedas is credited to Brahma. There are four Vedas: the Rigveda, the Yajurveda, the Samaveda and the Atharvaveda. Each Veda has been subclassified into four major text types – the Samhitas (mantras and benedictions), the Aranyakas (text on rituals, ceremonies, sacrifices and symbolic-sacrifices), the Brahmanas (commentaries on rituals, ceremonies and sacrifices), and the Upanishads (text discussing meditation, philosophy and spiritual knowledge). Some scholars add fifth category – the Upasanas (worship). The various Indian philosophies and denominations have taken differing positions on the Vedas. Schools of Indian philosophy which cite the Vedas as their scriptural authority are classified as "orthodox" (āstika). Other Sramana traditions, such as Lokayata, Carvaka, Ajivika, Buddhism and Jainism, which did not regard the Vedas as authorities are referred to as "heterodox" or "non-orthodox" (nāstika) schools. Despite their differences, just like Sramana traditions, various Hindu traditions dwell on, express and teach similar ideas such as karma (retributive action) and moksha (liberation) in the fourth layer of the Vedas – the Upanishads.