Kanji: Pictograph written language acquired from the Chinese
Hiragana: Japanese phonetic written language used instead of Kanji.
bonus:
Katakana: Japanese phonetic written language most often used for foreign (loan) words (computer, pencil, elevator, etc.)
Hiragana and Katakana are closely related written languages, you can easily equate them to print and cursive in English (except that Japanese has a common usage purpose for each). Katakana characters are generally straight lines while Hiragana phenoms are curved. Each Hiragana and Katakana character is (except for vowels and "n" a consonant (k,s,t,n,h,y,r,w) and a vowel (a,e,i,o,u) sound combined (i.e. Ra, Re, Ri, Ro, Ru).
There are also several forms of "Romanji" or ways to write the spoken Japanese language using English language characters. To the best of my limited knowledge there is not an "official" set of rules for Romanji but there is a couple that are most often used.
You now know more that you probably ever wanted to about written Japanese.