A beginner who is introduced for the first time to the study of later Sanskrit literature is likely to appear somewhat confused when he meets with authoritative texts of diverse purport and subjects having the same generic name "Veda" or "S'ruti" (from s'ru to hear); for Veda in its wider sense is not the name of any particular book, but of the literature of a particular epoch extending over a long period, say two thousand years or so. As this literature represents the total achievements of the Indian people in different directions for such a long period, it must of necessity be of a diversified character. If we roughly classify this huge literature from the points of view of age, language, and subject matter, we can point out four different types, namely the Sa@mhitâ or collection of verses (sam together, hita put), Brâhma@nas, Âra@nyakas ("forest treatises") and the Upani@sads. All these literatures, both prose and verse, were looked upon as so holy that in early times it was thought almost a sacrilege to write them; they were therefore learnt by heart by the Brahmins from the mouth of their preceptors and were hence called s'ruti (literally anything heard). [Footnote ref 4].