The Concise Oxford Dictionary of World Religions (2340 page)

(Skt., ‘that which is heard’). In Hinduism, sacred and eternal truth, now in the form of revelation. As the word implies, this revelation was ‘heard’ (or alternatively ‘seen’) by seers (
is
) in a mythical past and transmitted orally, now by
brahmans
. It is completely authoritative because
ruti is believed to be eternal, unmarked by human redaction, and only written down in the age of disorder. Thus it is distinguished from
sm
ti
, ‘that which is remembered’, this latter being sacred and of divine origin, but imperfect because it is an indirect form of revelation.
ruti
is synonymous with the
Veda
. Sm
ti in its widest application includes the
Ved
nga
, the ritual
s
tras
, the lawbooks, the
itih
sas
, the
Pur
as
, and the N
ti