This research attempts to distinguish the definitions of foresight and prediction and the differences between them based upon literature reviewing of fundamentals of futures studies and their historical background. In this respect, we introduced foresight schools and explained the role of scenario planning in foresight. Also, We addressed the quantitative and qualitative foresight methods, advantages and disadvantages, and reviewed the rational numbers of scenarios and criteria to validate scenarios. From the methodological point of view, this paper is a descriptive-analytical one, in which the history of future researches and foresight and their methods were introduced and compared. Depending on the purpose and scope of the project, different foresight methods are proposed. Major approaches to scenario planning were reviewed, and their strengths and weaknesses were analyzed. Attempts to explain and illustrate the concepts showed that scenario-based approaches that use both quantitative and qualitative methods together are more efficient than single qualitative or quantitative methods and their results are more valid for scenario planning. According to the analysis, considering details and data management, three to five scenarios seem reasonable. Finally, to validate scenarios, “internal consistency” and “plausibility” are the most popular and used validation criteria in scenario planning.