An alphabet is a set of characters intended to represent the sounds of spoken language (from the Greek alpha and beta). Because of this intention (which in practice is never realized) written languages employing alphabets are quite distinct from those using characters which represent whole words (such as hieroglyphics). The word alphabet is, however, usually extended to describe syllabaries, languages in which characters represent syllables. The chief alphabets of the world are Roman (Latin), Greek, Hebrew, Cyrillic (Slavic), Arabic, and Devanagari.
Alphabets probably originated around 2000 BC. Hebrew, Arabic, and other written languages sprang from a linear alphabet which had appeared c. 1500 BC. From the Phoenician alphabet, which appeared around 1700 BC, was derived the Greek. Roman letters were derived from Greek and from the rather similar Etruscan, also a descendant of the Greek. Most of the letters we now use are from the Latin alphabet, U and W being distinguished from V, and J from I, in the early Middle Ages. The Cyrillic alphabet, used with the Slavic languages, derives from the Greek. It is thought that Devanagari was possibly invented to represent Sanskrit.
Chinese and Japanese are the only major languages that function without alphabets, although Japanese has syllabary elements.