Event

A subset of the sample space $S$. We say that event $A$ occurred if the actual outcome is in $A$.

Context

Events are the building blocks of probability theory. For example, when rolling a die, the sample space is $S=\{1,2,3,4,5,6\}$ and “rolling an even number” is the event $A=\{2,4,6\}$. Events can be combined using union, intersection, and complement operations.

See Also

• sample space
• conditional probability
• variance