In line with a distinction popularized by writers such as Ardoino (1984), Bonniol (1988) and Bonniol and Genthon (1989) in France, the following reflection attempts to show that the concept of effectiveness belongs to "the order of aims" (i.e., of intentions or objectives aimed at) while the concept of efficiency belongs to "the order of programmation" of inputs and outflows. The outflows are the same for effectiveness and efficiency whereas the inputs are different. Effectiveness has intended effects as inputs, whereas invested resources are the inputs in efficiency. In both cases, we can distinguish quantitative components (intended quantitative effects or/and achieved effects, such as the number of diploma holders, quantitative resources expressed in financial costs) and qualitative components (intended and achieved effects expressed in terms of types of performance, non material resources, etc.). In addition, we can differentiate the internal and external facets of effectiveness and efficiency if we are interested in effects as related, respectively, to intentions or to invested resources. We will further try to show that equity, which also has internal and external facets, takes into account additional questions such as the distribution of costs and the advantages derived from educational investments.