Hiragana and Katakana are the lettering systems the Japanese use. They have three forms: Hiragana, Katakana, and Kanji. Kanji is similar to Chinese characters, except for slight variations. Hiragana is used to write words relating with Japan. Katakana is used to write words relating to English. For instance, the word "android" would be written in Katakana because "android" is an English word. The word "arigatou" would be written in Hiragana because "arigatou" is Japanese. Does this make sense? I'm never very good in explaining things.

I hope you understand! If not, you can ask me again and I'll try to help.