On 25 June, 2007, the fields medalist Tao posted a paper as a blog, titled "Ultrafilters, nonstandard analysis and epsilon management" where he explained why nonstandard analysis was introduced naturally, and gave applications of nonstandard analysis by him to PDE and number theory to shorten the proofs. In this talk, we will further explain nonstandard analysis offering a new tool to help discover new theorems, and to treat problems from the physical world, mathematically rigorously, which seem impossibly to be treated by standard analysis. Thus we believe that nonstandard analysis is a new tool for describing the nature, it manages usual numbers, infinitesimals and infinities coming from the nature!