Characters carry the original meaning consistent with their glyphs, and at the same time, they also carry extended but undifferentiated extended meanings, which is their inherent function.
However, when characters are used, their function of memorizing words often changes. One of the most important reasons is that when some documents use Chinese characters, there is often a phenomenon of borrowing the same sound.
That is to say, in the process of using Chinese characters, sometimes a word with the same sound or similar sound is used to replace the original word. We call the words borrowed to write this word or other words with the same sound or similar sound as the loanwords of this word or word. At this time, the position of the word shifted to loanwords.