Iterative methods are numerical techniques used to approximate solutions to mathematical problems that cannot be solved exactly or efficiently using traditional methods. These methods involve repeatedly refining an initial guess to gradually approach the true solution. Iterative methods are commonly used in various fields such as computer science, engineering, and physics, for solving systems of equations, optimization problems, and other types of numerical calculations. Examples of iterative methods include the Jacobi, Gauss-Seidel, and conjugate gradient methods. These methods are useful when the problem size is large, the system of equations is sparse, or when the exact solution is difficult to obtain.