It is, and means, the
Chinese characters. This conceptual writing system is believed to be totally archaic by the European linguistic experts who don't have a single idea about the whole thing. Their logic goes as follows, from the most primitive to their Latin:
pictures - hieroglyphs - kanji - syllabary (on the Cyprus island) - Greek - LATIN.
Which is a complete nonsense, to say at least. I will try to explain why KANJI is the best script for certain Asian countries and why it should come to our general knowledge as well.
When a language contains a lot of homophones, which is seen on a regular basis in Japanese and Chinese, putting it simply phonetically will not do for more complex texts. So the text is much more clear with the glyphs. It shall also be taken into
consideration that different scripts are optimised for different audiences. Unlike Latin, which was developed for general public and needed to express tongue-twisting sounds, and is therefore good for fast learning (some children learn it in 1 week), the Kanji is targetted to well-educated and subsequently wise people. It is also proved that when one masters Kanji, he can absorb information 2 times faster than when reading Roman letters. But there's more: Unlike Latin letters, one can see
interesting coherences in the Kanji's radicals, which allow an experienced reader to
understand a new character without exactly remembering it, and, what's more
interesting, enrich their mind with
understanding how a difficult word can be made of the simpler ones.
Now one piece of information related strictly to the Japanese use of Kanji: They use both traditional and simplified variants of it, which may complicate simultaneous learning of Chinese and Japanese. They also include okurigana suffixes after the word roots to express the tense.