Katakana [1] is one of the two syllabary writing systems in Japanese, with Hiragana [2] being the other. IIRC katakana is the one where every syllable starts with a consonant and ends with a vowel, so transliterated loan words with consecutive consonants end up growing vowels in the middle. They also have kanji (characters), and various romanization systems (https://en.wikipedia.org/wiki/Romanization_of_Japanese). It's really amazingly inefficient.

[1] https://en.wikipedia.org/wiki/Katakana [2] https://en.wikipedia.org/wiki/Hiragana