Iteration

Iteration means repeating a process to generate a possibly unbounded sequence of outcomes, where each repetition is a single iteration and the outcome of each one is the starting point of the next. In mathematics it can mean applying a function repeatedly, using the output of one step as the input to the next, or the iterative methods that produce approximate numerical solutions to certain problems, of which Newton's method is an example. In computing it is a technique that marks out a block of statements within a program for a defined number of repetitions, most commonly through loops, with iterators and iteratees as alternative language constructs. Iteration is related to recursion: the two have different algorithmic definitions but can generate identical results, and the primary difference the source gives is that recursion can work without prior knowledge of how many times the action must repeat, while a successful iteration requires that foreknowledge.