In computer science a for-loop (or simply for loop) is a programming language control statement for specifying iteration, which allows code to be executed repeatedly. The syntax of a for-loop is based on the heritage of the language and the prior programming languages it borrowed from, so programming languages that are descendants of or offshoots of a language that originally provided an iterator will often use the same keyword to name an iterator, e.g., descendants of ALGOL use "for", while descendants of Fortran use "do." There are other possibilities, for example COBOL which uses "PERFORM VARYING".