With Condition/ Decision coverage the possible outcomes of each condition and of the decision are tested at least once. This implies both Condition coverage and Decision coverage. In other words we cover that all conditions are one time TRUE and one time FALSE and we cover one time the THEN and one time the ELSE.
Here it is relevant to vary in the outcome of the decision, and in the outcomes of the conditions. Since there are only two possible outcomes of a decision (THEN or ELSE), and there are only two outcomes of a conditon, test situations can be created in such a way that only 2 test situations per decision point are needed.
See the following animation for a more detailed explanation: