The term kana (仮名, Japanese pronunciation: [kana]) may refer to a number of syllabaries used to write Japanese phonological units, morae. Such syllabaries include (1) the original kana, or magana (真仮名, literally 'true kana'), which were Chinese characters (kanji) used phonetically to transcribe Japanese, the most prominent magana system being man'yōgana (万葉仮名); the two descendants of man'yōgana, (2) hiragana (平（ひら）仮（が）名（な）), and (3) katakana (片（カタ）仮（カ）名（ナ）). There are also hentaigana (変体仮名, literally 'variant kana'), which are historical variants of the now-standard hiragana. In current usage, 'kana' can simply mean hiragana and katakana.

Katakana, with a few additions, are also used to write Ainu. A number of systems exist to write the Ryūkyūan languages, in particular Okinawan, in hiragana. Taiwanese kana were used in Taiwanese Hokkien as glosses (ruby text or furigana) for Chinese characters in Taiwan when it was under Japanese rule.

Each kana character (syllabogram) corresponds to one sound or whole syllable in the Japanese language, unlike kanji regular script, which corresponds to a meaning (logogram). Apart from the five vowels, it is always CV (consonant onset with vowel nucleus), such as ka, ki, etc., or V (vowel), such as a, i, etc., with the sole exception of the C grapheme for nasal codas usually romanised as n. The structure has led some scholars to label the system moraic, instead of syllabic, because it requires the combination of two syllabograms to represent a CVC syllable with coda (i.e. CVn, CVm, CVng), a CVV syllable with complex nucleus (i.e. multiple or expressively long vowels), or a CCV syllable with complex onset (i.e. including a glide, CyV, CwV).

The limited number of phonemes in Japanese, as well as the relatively rigid syllable structure, makes the kana system a very accurate representation of spoken Japanese.