Among the six books, the first four are direct word-making methods, in which pictographic characters are the basis of the six books, followed by things, meanings, shapes and sounds, and the methods of transferring notes and borrowing words are different from the first four word-making methods. "Pictograph" is to describe an actual thing according to the simplest symbol or image, and to express the meaning represented by words through shapes. For example, sun, moon, mountain, stone, field and fire are all pictographs created according to the shape of things.
Now some pictographs are not obvious, but some can still be seen. Although there are fewer pictographs now, they still occupy a high position in the evolution of Chinese characters and are the basis of Chinese characters. For example, "horse" is a word-formation component of the words "donkey, pack and drive", and their meanings can be seen from their shapes.
But hieroglyphics, after all, have their own limitations and can't meet the rich language needs, so there are later words.