Japanese Language

日本語の表記  Japanese Characters 

As you walk around Japan or leaf through Japanese books or newspapers, you will notice that Japanese orthography employs several different sets of characters, including the Latin alphabet as well as some others of differing degrees of complexity.  As you see in the pictures below (train station sign and a poster), there are four types of characters used in the Japanese language.  Among those, Hiragana, Katakana, and Kanji are Japanese writing systems.
(picture on the left)
東京-Kanji (Chinese characters): Most complicated in appearance
とうきょう-Hiragana: Curvilinear characters
Tokyo-Romaji (Romanization): Written using the Latin alphabet

(picture on the right)
カラオケ-Katakana: Angular characters

Japanese today uses a mixture of Kanji logograms and kana sound symbols.  The bulk of Japanese writing is done in Kanji and Hiragana.  Katakana is used primarily for words borrowed from foreign languages, though it is also used for onomatopoeia, memeic words, and sceientific names of animals and plants as well as for indicating emphasis.
Romaji (Romanization), at first glance much like English, is a system for transliterating sounds in Japanese according to set rules.  They were originally used for foreigners to be able to read Japanese, but nowadays, they are used as a fashion as well.