Hiragana and katakana are both kana systems; they have corresponding character sets in which each kana, or character, represents one mora (one sound in the Japanese language). Each kana is either a vowel such as "a" (hiragana あ); a consonant followed by a vowel such as "ka" (hiragana か); or "n" (hiragana ん), a nasal sonorant which, depending on the context, sounds either like English m, n, or ng ([ŋ]), or like the nasal vowels of French. Because the characters of the kana do not represent single consonants (except in the case of ん "n"), the kana are referred to as syllabaries and not alphabets.
The modern Japanese writing system uses a combination of three main scripts:
Several thousand kanji are in regular use, while in modern Japanese the two syllabaries each contain 46 basic characters (71 including diacritics), each representing one sound in the Japanese language. Almost all Japanese sentences contain both kanji and hiragana, while some additionally use katakana. Because of this mixture of scripts in addition to a large inventory of kanji characters, the Japanese writing system is often considered to be the most complicated in use anywhere in the world.
To a lesser extent, modern written Japanese also uses acronyms from the Latin alphabet, for example in terms such as "BC/AD", "a.m./p.m.", "FBI", and "CD". Romanized Japanese, called rōmaji, is frequently used by foreign students of Japanese who have not yet mastered the three main scripts, and by native speakers for computer input.
The Japanese writing system allows for transmitting information that is usually communicated in other languages by using different words or by adding extra descriptive words. For example, writing a word in English may give it a modern or 'hip' flair.