Katakana (カタカナ) is one of the Japanese wrting system along with Hiragana and Kanji. As well as Hiragana, Katakana is phonetical and is a simplified form of Kanji.
Katakana is mainly used in modern Japanese language when a word describes foreign language or names.
Ex: Television – テレビ (terebi)
Coffee – コーヒー (koohii)
Penelope Cruz – ペネロペ・クルス (Peneroepe Kurusu).
More about Japanese language