The main difference between them is that high school mathematics mainly studies finite operations, while most operations in higher mathematics are infinite. For example, high school mathematics is to find the value of a function; Advanced mathematics is calculus for finding functions (the model is to find the area between functions and coordinate axes, and the "orthodox" method for finding the area is to divide it into infinite small "rectangles" and then add them up). Senior high school mathematics learns some simple methods of sequence summation, while advanced mathematics begins to study the nature of sequence summation-to see if it has a limit, what is the limit and so on. In a word, high school mathematics is the foundation of higher mathematics in colleges and universities. If the foundation of high school mathematics is weak, it is very difficult to learn advanced mathematics. It often happens that you know all the theorems, but you know nothing (which is a bit extreme, of course). Some very basic things in high school mathematics, such as product and exchange of trigonometric functions, angle transformation and angle multiplication formula; Exponential function, common formula of logarithmic function; The general term of sequence, the method of summation and so on are very important for the study of advanced mathematics.