Writing system
A writing system comprises a particular set of symbols, called a script, as well as the rules by which the script represents a particular language. Writing systems can generally be classified according to how symbols function according to these rules, with the most common types being alphabets, syllabaries, and logographies. Alphabets use symbols called letters that correspond to spoken phonemes. Abjads generally only have letters for consonants, while pure alphabets have letters for both consonants and vowels. Abugidas use characters that correspond to consonant–vowel pairs. Syllabaries use symbols called syllabograms to represent syllables or moras. Logographies use characters that represent semantic units, such as words or morphemes.
For broader coverage of this topic, see Writing.
Alphabets typically use fewer than 100 symbols, while syllabaries and logographies may use hundreds or thousands respectively. Writing systems also include punctuation to aid interpretation and encode additional meaning, including that which is communicated verbally by qualities such as rhythm, tone, pitch, accent, inflection or intonation.
Writing was first invented in the late 4th millennium BC. Each independently invented writing system in human history evolved from a system of proto-writing not fully capable of encoding spoken language. These systems used a small number of ideograms, but were not fully capable of encoding spoken language, and lacked the ability to express a broad range of ideas.
Graphic classification[edit]
Perhaps the primary graphic distinction made in classifications is that of linearity. Linear writing systems are those in which the characters are composed of lines, such as the Latin alphabet and Chinese characters. Chinese characters are considered linear whether they are written with a ball-point pen or a calligraphic brush, or cast in bronze. Similarly, Egyptian hieroglyphs and Maya glyphs were often painted in linear outline form, but in formal contexts they were carved in bas-relief. The earliest examples of writing are linear: the Sumerian script of c. 3300 BC was linear, though its cuneiform descendants were not. Non-linear systems, on the other hand, such as braille, are not composed of lines, no matter what instrument is used to write them.
Cuneiform was probably the earliest non-linear writing. Its glyphs were formed by pressing the end of a reed stylus into moist clay, not by tracing lines in the clay with the stylus as had been done previously.[22][23] The result was a radical transformation of the appearance of the script.
Braille is a non-linear adaptation of the Latin alphabet that completely abandoned the Latin forms. The letters are composed of raised bumps on the writing substrate, which can be leather (Louis Braille's original material), stiff paper, plastic or metal.
There are also transient non-linear adaptations of the Latin alphabet, including Morse code, the manual alphabets of various sign languages, and semaphore, in which flags or bars are positioned at prescribed angles. However, if "writing" is defined as a potentially permanent means of recording information, then these systems do not qualify as writing at all, since the symbols disappear as soon as they are used. (Instead, these transient systems serve as signals.)