Approximation is a research area that involves finding simplified or approximate solutions to complex mathematical problems that are difficult or impossible to solve exactly. This can involve using numerical methods, algorithms, or other techniques to find a solution that is close enough to the exact solution for practical purposes. Approximation methods are commonly used in a variety of fields including computer science, physics, engineering, and economics. The goal of approximation research is to find efficient and accurate methods for solving problems that may be too challenging to solve using exact methods.