In a dilemma or trilemma one is faced with a difficult decision.
In a dilemma one is faced with two choices but can only select one (OR).
In a trilemma one is faced with three choices but can only select one or two of them.
The decision is only difficult if:
(1) the choices are about equal and
(2) the choices are either all desirable or all undesirable
One classic example is a business trilemma, where the client has to choose two items from fast, cheap and good quality.
