Written Japanese has 4 different alphabets. 3 of them are listed on this site- hiragana, katakana, and kanji. The 4th one is romaji, or the romanized version of the Japanese syllables. This may sound like a lot to learn, but if you think about it, written English also has 4 different alphabets- cursive and print, both uppercase and lowercase. With just a little practice, it's not hard to learn when to switch from one to the other. I've included a little about the main 3 here, but if you'd like to see a site that goes much more in depth, I suggest you visit the KanjiSite.