Written Chinese emerged in its embryonic form of carved symbols approximately 6,000 years ago. The Chinese characters used today evolved from those used in bone and tortoise shell inscriptions more than 3,000 years ago and the bronze inscriptions produced soon after. Drawn figures were gradually reduced to patterned stroke, pictographs were reduced to symbols, and the complicated graphs became simpler. Early pictographs and ideographs were joined by pictophonetic characters.
In fact, there are six categories of Chinese characters: pictographs, self-explanatory characters, associative compounds, pictophonetic characters, phonetic loan characters, and mutually explanatory characters.