Disregarding combinatorial optimization as an attractive platform for academic careers , the three main justifications for the current and steadily increasing interest in the field are: - the variety of realistic decision problems amenable for modeling and analysis via combinatorial optimization - the lack of 8 universal, operational algorithm - other theoretical challenges First. the nature of a combinatorial optimization problem is accounted for. To substantiate the significance of such problems to decision-makers in practice, an overview of the most profitable application areas as well as the most applicable problem types is then provided. Past history is briefly reviewed within the framework of an annotated bibliography. We close with subjective views as to today's challenges and to what is believed to be tomorrow's main issues of concern.