Iterative algorithms are a class of algorithms that are used to solve complex problems by repeating a series of steps in order to converge to a solution. These algorithms work by starting with an initial guess or estimate of the solution and then repeatedly refining this estimate until a desired level of accuracy is achieved. Iterative algorithms are commonly used in a variety of fields, such as optimization, numerical analysis, machine learning, and signal processing. They are particularly useful when the problem at hand cannot be solved analytically or when the size of the problem is too large to be solved in a single step. Iterative algorithms are often preferred over direct methods in such cases because they are more efficient and can handle larger and more complex problems.