1, writing. The purpose of the paper is mainly to explain the problem to be solved in the paper, that is, why to choose such a topic to discuss and what to discuss. The writing of the thesis theme mainly focuses on the influence of the problem-solving effect.

2. motivation. The purpose of the paper is entirely the author's subjective motivation, which depends on the author. Although some writing purposes can be seen from the article, it is still based on the author's subjective purpose. The theme of the paper is implicit in the article, extracted from the article and objective. Every article has a theme.