The geometric significance of improper integral's existence: When there is a limit between the function and the area around the X axis, the area can be found even if the function value is infinite at one point.

Generalized integral, also known as generalized integral, is a generalization of ordinary definite integral, which refers to integral with infinite upper and lower bounds or defective integrand function. The former is called infinite generalized integral, and the latter is called loss integral (also called improper integral of unbounded function).