"In mathematics and computer science, an algorithm ... is a step-by-step procedure for calculations. Algorithms are used for calculation, data processing, and automated reasoning.
An algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Starting from an initial state and initial input (perhaps empty), the instructions describe a computation that, when executed, proceeds through a finite number of well-defined successive states, eventually producing "output" and terminating at a final ending state. The transition from one state to the next is not necessarily deterministic; some algorithms, known as randomized algorithms, incorporate random input." [Algorithm. Wikipedia]
The algorithm flow chart example "Selection sorting method" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Flowcharts solution from the area "What is a Diagram" of ConceptDraw Solution Park.