The
sample space, often denoted
S or
U (for "universe") of an experiment is the
set of all possible outcomes of a single experiment. For example, if the experiment is tossing a coin, the sample space is the set {head, tail}. For tossing a single die, the sample space is {1, 2, 3, 4, 5, 6}.
Each element in the sample space is called an /Elementary event, while every subset of the sample space is called simply an /Event.