Abugida vs. Abjad — What's the Difference?

An abugida ( (listen), from Ge'ez: አቡጊዳ), sometimes known as alphasyllabary, neosyllabary or pseudo-alphabet, is a segmental writing system in which consonant-vowel sequences are written as units; each unit is based on a consonant letter, and vowel notation is secondary. This contrasts with a full alphabet, in which vowels have status equal to consonants, and with an abjad, in which vowel marking is absent, partial, or optional (although in less formal contexts, all three types of script may be termed alphabets).

An abjad (, Arabic: أبجد; also abgad) is a writing system in which only consonants are represented, leaving vowel sounds to be inferred by the reader. This contrasts with other alphabets, which provide glyphs for both consonants and vowels.

(linguistics) A kind of syllabary (syllabic alphabet) in which a symbol or glyph representing a syllable contains parts representing a vowel and a consonant, such that symbols for syllables not including the default vowel are generated by adding a common notation to indicate the vowel that it does include.

A writing system for Arabic, historically also employed as a numeral system, in which there is one glyph (symbol or letter) for each consonant but vowels are not specified.

(linguistics) A kind of syllabary (syllabic alphabet) in which a symbol or glyph representing a syllable contains parts representing a vowel and a consonant, typically such that symbols for different syllables are generated by adding, altering or removing the vowel portion, often by applying a diacritic to a stable consonant symbol.

(linguistics) Any writing system in which glyphs are used to represent consonants or consonantal phonemes, but not vowels.

The system of abjad numerals; a numeral system in which the letters of the Arabic abjad are interpreted as numerals, typically used to enumerate lists and nested lists, as well as in numerology.