Nihongo is the national language spoken in Japan, although I know there are many ethnic groups who are using different languages. Nihongo is I think a combination of 2 words Nihon and gengo which literally means: Nihon（日本）= Japan + Gengo = Language = Japan Language. According to history most of the characters used by the Japanese are originally from China, the reason why if you will compare the characters of the 2 language, certain similarities will be observed (that's why a Chinese friend of mine adapt with it so easilly :-D).
Nihongo language is represented in 3 sets of characters: Hiragana, which is the usual way to write Japanese entities, etc (eg. Books=hon=ほん); Katakana, which is used to write foreign words like my name Edward (Edowarudo＝エドワルド :-?); and finally Kanji, which like I said originates from Chinese, Hiragana can also be represented in Kanji (eg. book=hon=ほん=本). Oftentimes Kanji writings shorten an object written representation :-D. But it's hard to memorize and I think there are thousands of them (if I remember right, I only know about 700 of them).
Compared to the set of alphabet that we usually know (BTW I'm a Filipino and our alphabet set is almost like that of the English -a b c.. etc), don't you think that's too much? Hiragana and Katakana has around 45 each + hundreds or even thousands from Kanji :-D.. Nevertheless I enjoy learning it. Writing their character is like an art, I remember when I was in college I always got low grades on writing cause my sensei was very specific on strokes.
Well, that's the basic Nihongo Language for you. In the future I will try to discuss each set one by one with examples :-D.