Written Japanese consists of three main 'alphabets': Kanji, Hiragana and Katakana. Technically they aren't alphabets, but calling them syllabaries and logographs just complicates things, and the one thing you want to avoid right now is complicating things unnecessarily. Sentences contain a mixture of all three alphabets, but don't worry as it's pretty easy to tell them apart.
Hiragana is the basic 'alphabet' of Japanese, and it contains all the basic sounds used throughout the language. In Japanese, unlike in English, there is no ambiguity with how each character is pronounced. The cool thing about this is that after learning Hiragana, you know the correct pronunciation of any written word in Japanese.
Katakana is exactly the same as Hiragana, it's just written differently, like how ‘e' and ‘E' are the same letter in English. Katakana has a few uses in written Japanese, such as loanwords from other languages and onomatopoeia (words that resemble sounds eg: 'tic toc').
Kanji are the characters adopted from Chinese. There is a LOT of them, you'll need to learn over 2000 to read a newspaper, and most of them can be pronounced multiple ways. Kanji makes up all of the nouns (eg: people, places, things), verbs (eg: bring, happen, stand) and adjectives (eg: interesting, ugly) in the written language.
There exists a fourth way of writing Japanese, Romanji. This is just writing out Japanese words using the English alphabet. Words like 'sake' and 'karate' are examples of this. It is not used in Japan and can cause issues in not learning Japanese pronunciation correctly so it is not really worth studying. You will learn it in passing, but we'll be jumping as quickly as possible to reading and writing in real Japanese, so don't give it much thought.
An easy way to tell the characters apart is to know that Kanji are the characters with many complex strokes, Hiragana is simpler and curvy while Katakana is simpler and has sharper edges. Tho soon after you learn Hiragana and Katakana you can easily detect Kanji as "the ones I don't know".
Now that you have a basic overview of written Japanese, you're ready to jump right in, so head over to the next lesson to begin learning Hiragana.
Image Credit Ryosuke Sekido.