By definition, alternating current flows in one direction, then alternates,flowing in the opposite direction through a circuit. Unfiltered rectifiedDC (pulsating DC) flows unidirectionally through the load circuit.Your question did not specify smooth DC. While filtered DC in the vast majority of applications is generally required,some, like my electrolysissupplies omitthe filter. Others such as lamp and simple LED drivers and battery chargersdo not require them. I am along timewriter anddesignengineer and I'mvery picky about precise language usage, particularly when my egogets involved. I do think Ishould be givencredit for my answer.