The cuneiform script is one of the earliest known forms of written expression. Created by the Sumerians from ca. the 34th century BC, cuneiform writing began as a system of pictographs. Over time, the pictorial representations became simplified and more abstract.
Cuneiforms were written on clay tablets, on which symbols were drawn with a blunt reed called a stylus. The impressions left by the stylus were wedge shaped, thus giving rise to the name cuneiform ("wedge shaped").
The Sumerian script was adapted for the writing of the Akkadian, Elamite, Hittite (and Luwian), Hurrian (and Urartian) languages, and it inspired the Old Persian and Ugaritic national alphabets.
Originally, pictograms were drawn on clay tablets in vertical columns with a pen made from a sharpened reed stylus, or incised in stone. This early style was still lacking the characteristic wedge-shape of the strokes.
From about 2900 BC, the pictographs began to lose their original function, and a given sign could have various meanings depending on context. The sign inventory was reduced from some 1,500 signs to some 600 signs, and writing became increasingly phonological. Determinative signs were re-introduced to avoid ambiguity. This process is directly parallel to, and probably not independent of, the development of Egyptian hieroglyphic orthography.