Difference between hiragana and katakana

katakana; is a Japanese syllabary used primarily for loanwords

(Meaning katakana is used when the word comes from another language such as a hamburger or a name for example rose.  they don't have the japanese translation, so they use katakana).

Hamburger ( hambaーgaー) they pronounce it like that)

Rose ( rosu)

hiragana; is a Japanese syllabary used primarily for native Japanese words 

(hiragana is used in words derived from the japanese word)  

Now ( ima- いま)

Tomorrow ( ashita あした)

Then kanji (漢字)is a Chinese characters

Ima (いま／今) now 

Ashita (あした/ 明日) tomorrow