First of all, high school calculus mainly focuses on the basic concepts of limit, derivative and integral and their applications. These applications mainly include solving practical problems, such as speed, acceleration, area and volume. The focus of calculus in senior high school is to cultivate students' intuitive understanding and basic calculation ability, so that they can apply these concepts to solve simple practical problems.

In contrast, college calculus is more in-depth and extensive. It covers more advanced concepts such as limit, derivative and integral, such as derivative, partial derivative and multiple integral of multivariate function. The focus of college calculus is to cultivate students' abstract thinking and theoretical analysis ability, so that they can understand and prove more complex mathematical theorems and formulas.

In the field of mathematics application, the application scope of college calculus is wider. It can be applied to physics, engineering, economics, computer science and many other fields. For example, in physics, calculus can be used to describe the movement of objects, the action of forces and the change of energy; In engineering, calculus can be used to optimize the design and control system; In economics, calculus can be used to study the relationship between supply and demand and marginal effects; In computer science, calculus can be used for image processing and machine learning.

In addition, college calculus also involves some advanced mathematical tools and methods, such as series, Fourier series, Laplace transform and so on. These tools and methods can be applied to more complex mathematical problems such as signal processing, probability theory and statistics.

In a word, there are some differences between high school calculus and college calculus in the field of mathematical application. High school calculus mainly focuses on the basic concepts of limit, derivative and integral and their applications, while college calculus is more in-depth and extensive, covering more advanced mathematical concepts and methods and being applied to many disciplines.