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.

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.