Mathematics can generally be divided into elementary mathematics and advanced mathematics. Elementary mathematics is the content of mathematics learned in high school and before, and those are the fur of mathematics; Advanced mathematics is a mathematical research model based on calculus. It can be said that the invention of calculus is the greatest invention in human history. Without calculus, it is estimated that we still lived hundreds of years ago.

Of course, there are many branches of mathematics, such as probability and mathematical statistics, linear algebra, analytic geometry, discrete mathematics, complex variable function, Riemannian geometry, extension and complement set, and relatively new fuzzy mathematics (fuzzy mathematics is the basis of intelligent computers) ... Of course, there are many more, but my knowledge space is limited, and I only dabble in this respect, which can only help you. (In addition, the mathematical and physical equations are actually the solutions of partial differential equations (groups). It is only a simple application of mathematics in physics, and I don't think it should be regarded as a classification of mathematics.