The control structure is the name given to one of the instructions, statements, or groups of statements in a programming language that coordinates the sequence in which another instruction or statement is executed.

The path from control statement to the execution of the function is known as the control flow. The control structure is especially useful when the control flow is not sequential--when certain instructions in the sequence need to be repeated, or when some instructions in a sequence are only executed under certain conditions. The use of control structures allows the program's control flow to be altered in a controlled fashion.

The executed statement is typically in response to a user command (also known as an event-driven command). For example, when a graphic icon, such as a button, is pressed, a control structure is activated to coordinate the execution of whatever function is associated with...