Kanji symbols originated in China. These Kanji symbols (家事）. These characters are units of meaning. Developed for representing words such as picture symbols. In Japan they are commonly used for nouns, numbers and measuring units.
An Example is Japan. The Japanese call Japan Nihon Nee Hon written in Kanji it is 日本 but the Japanese can also write it in Hiragana ひらがな。 Native Words can be written in either Kanji or Hiragana. Kanji is more common .There are thousands of Kanji. Kanji symbols have no indication on how they are pronounced or their meaning so they must be memorised. Japanese children learn about 2000 by the time they leave Primary school. 3000 Kanji is commonly required for reading a newspaper.