The Japanese writing system is originally based on Chinese ideograph script. These often complicated characters (consisting of up to two dozen so-called brush strokes) are called kanji and each represent a full word or concept. There are 2,136 recognised kanji, with an additional 983 showing up in proper names.
As opposed to Chinese, Japanese also uses two phonetic syllabaries. Hiragana is a flowing longhand-like script and is used for propositions, small particles without a (simple) kanji and for prefixes and suffixes to kanji to (among others) conjugate verbs or indicate grammatical case, politeness level or verb tense. Hiragana consists of 46 characters, each a syllable.
Katakana is a more angular script and is mainly used to write foreign loanwords and onomatopeia or as an equivalent to all caps. Katakana has 48 glyphs, mostly corresponding to the hiragana ones.