When we talk about the origin of Chinese characters, there are basically two sharply contrasting opinions. The first idea that the students who learn Mandarin should know is proposed by Tang Lan in the 1930s. He said the Chinese characters existed in the early years of Xia Dynasty. Later, he summarized that the most ancient native characters were the characters to express meanings by drawings. When you learn Mandarin, you should also know that Guo Moruo proposed the theory of self-explanatory characters on the basis of inscription on pottery of Yangshao Culture.
About the inscriptions on pottery, the scholar Li Xiaoding thought the origin of Chinese characters can be explored from the pottery inscriptions. As the research deepens, the foreigners who learn Mandarin Chinese should know that the importance of geometric symbols and glyphs in origin of characters is different. Some further research provided support to the theory that inscriptions on pottery were the origin. Some students who learn Mandarin may also hear some other origins like tying knots and the Eight Diagrams. However, the main viewpoints are the drawings and symbols and more research is needed to prove.