The present paper speaks about the main theoretical aspects connected to the decisional environment. Thus, we defined the decision and its major role in the managerial process. Secondly we followed the stages and perception along time in defining the concept of decision. After that we described, shortly, the factors which diminish the uncertainty: relevance, correctness, accuracy, precision, completion, timing, usage, consistency, conformity and cost. The next treated aspects were several classifications of the decisions, taking into account different variables or implied elements. In the end we jump at the conclusions.