Chapter 1 KATAKANA
Katakana is primarily used to represent foreign words, except Chinese words, which, of course, are written in kanji. And this is exactly why we introduce katakana, first, instead of hiragana. Most of the words which are actually written in katakana are words which are more likely familiar to you, such as non-Japanese names, country names, various items, etc. Also, by expressing those familiar words in katakana, you should be able to know how different the Japanese pronunciation is, as compared with the original pronunciation.