Japanese Kanji
Between 5,000 and 10,000 Chinese characters, or kanji, are used in written Japanese. In 1981 in an effort to make it easier to read and write Japanese, the Japanese government introduced the jōyō kanji hyō (List of Chinese Characters for General Use), which includes 1,945 regular characters, plus 166 special characters used only for people's names. All government documents, newspapers, textbooks and other publications for non-specialists use only the these kanji. Writers of other material are free to use whatever kanji they wantJapanese children are expected to know all of the jōyō kanji by the end of high school but to read specialist publications and ordinary literature, they need to know another two or three thousand kanji.
When the Japanese adopted Chinese characters to write the Japanese language they also borrowed many Chinese words. Today about half the vocabulary of Japanese comes from Chinese and Japanese kanji are use to represent both Sino-Japanese words and native Japanese words with the same meaning.
For example, the native Japanese word for water is mizu while the Sino-Japanese word is sui. Both are written with the same character. The former is known as the kun yomi (Japanese reading) of the character while the latter is known as the on yomi (Chinese reading) of the character.
for example: - ほん(hon)= book