In general language, possible outcomes are results that may occur by performing some task. Possible outcomes are used in math, specifically in probability, to determine what results could exist.
Possible outcomes are important in decision making because in order to make a decision, a person has to know the available options. However, strictly speaking, options are not the same as possible outcomes. Possible outcomes are the results of options. In other words, in a decision of whether to go to school, the options are to go or not go. The possible outcomes are all of the things that could result from those options.
A person might use "possible outcomes" when analyzing a probability problem. For example, the possible outcomes of a coin toss are heads or tails. For a standard die, there are six possible outcomes (i.e., the six faces of the die). In probability, the counting principle is used to determine the number of possible outcomes. In problems more complex than the ones stated above, possible combinations are multiplied. For example, the possible outcomes of two consecutive coin tosses would be 2 x 2 = 4 (heads or tails for the first toss, and heads or tails for the second). The possible outcomes would then be HH, HT, TH, and TT. This principle can be extended indefinitely. For example, the number of possible outcomes of a coin toss and a die roll would be 2 x 6 = 12 (H or T, and 1-6).