Abjads differ from alphabets in that vowels are not indicated, and in abugidas or alphasyllabaries each character represents a consonant–vowel pairing.Īlphabets typically use a set of less than 100 symbols to fully express a language, whereas syllabaries can have several hundred, and logographies can have thousands of symbols. In a logography, each character represents a semantic unit such as a word or morpheme. In a syllabary, each symbol correlates to a syllable or mora. In the alphabetic category, a standard set of letters represent speech sounds. Writing systems can be placed into broad categories such as alphabets, syllabaries, or logographies, although any particular system may have attributes of more than one category.
Reading a text can be accomplished purely in the mind as an internal process, or expressed orally. Writing is usually recorded onto a durable medium, such as paper or electronic storage, although non-durable methods may also be used, such as writing on a computer display, on a blackboard, in sand, or by skywriting. Writing systems require shared understanding between writers and readers of the meaning behind the sets of characters that make up a script. While both writing and speech are useful in conveying messages, writing differs in also being a reliable form of information storage and transfer. A writing system is a method of visually representing verbal communication, based on a script and a set of rules regulating its use.