What is the diffrence between hiragana and katakana?


I am just a begginer. I finished learning Hiragana . Now , I am learning
Katakana . I realized that they are same. So that made me worry a little . How
do I decide which one to choose ? Are there any words that you cant use
katakana instead of hiragana or hiragana instead of katakana letters in them ?
Also, If write it like that will Japanese people can understand what I meant ?




Words of non-Chinese foreign origin are generally written in katakana, for one
thing. Besides that, there a few Japanese words it's quite common to write in
katakana, such as オシャレ and ダメ. In some works of fiction, a character's
dialogue may be written in katakana to project a 'robotic' or 'otherworldly'
tone.

