Iteration is a characteristic of certain algorithms or computer programs in which a sequence of one or more algorithmic steps are performed in a program loop. It is distinguished from the repetitive technique called recursion.

Here is an example, in pseudocode:

   a = 0
   for i = 0 stepby 1 until 3
       a = a + i
   print a  /* "6" is printed */

A process which is repeated again and again it know as a reiterative process. Reiteration is often used in order to converge on the final result when starting with an educated guess.

See also: Iterative and Incremental development -- iterator -- Iterative method -- Nash embedding theorem