Katakana used for training and reading appeared in Heian period, but katakana fonts were unified in Meiji period. Before that, a pronunciation often had multiple katakana corresponding to it.
Hiragana was born to write songs and stories. The main users are women, so they are also called "female roles". For many years, court women copied Ye Wan Collection, and for a long time, the Chinese characters of Ye Wan's pen name have been gradually simplified to Hiragana.
2. Different uses
Use of katakana:
(1) Loanwords: proper nouns such as foreigners' names (except Japanese), foreign place names (except Japan) and all loanwords (except Japanese).
(2) Onomatopoeia: mimetic language. For example, the dog barks ワンワン, the cat barks ニヤニヤニヤヤロ, and the frog barks ケロ.
(3) Japanese names of organisms and minerals (the Japanese government has suggested that the names of animals and plants in academic fields should be expressed in katakana, but personal usage habits are not included in the specification).
Use of hiragana:
In modern Japanese, hiragana is often used to represent the vocabulary and grammatical auxiliary words inherent in Japanese, and hiragana is also commonly used when phonetic notation of Japanese Chinese characters, which is called vibrating kana.
3. Writing is different
Hiragana: Hiragana is derived from cursive script of Chinese characters and has a round appearance.
Katakana: Katakana comes from the regular script of Chinese characters, and it certainly looks angular.
Baidu Encyclopedia-Hiragana
Baidu Encyclopedia-Katakana