ALPHABET (through Lat. from Gr. alphabetos, derived from the initial two letters of the Gr. alphabet, alpha and beta). A series of conventional signs for transcribing the sounds of a language, each sign ideally representing one single sound. This concept must be distinguished from other forms of writing of which there are two main types; (a) the ideogram, which is a single, often complex sign signifying one word or idea, the sign itself being generally derived from the pictogram, a diagrammatic drawing of the thing signified by the word or illustrating its main aspect; and (b) the syllabary, which is a series of signs representing syllables, often consonant followed by vowel. These two forms of writing human speech, which still continue to be used, preceded strictly alphabetic writing (see article on Writing).