Indicator Variable

Given an event $A$, we have indicator variables corresponding to A, called $I_A$: $I_A=\{\begin{array}{ll}1,& \text{if }A\text{ occurs}\\ 0,& \text{if }{A}^C\text{occurs}\end{array}$

You can see that the indicator variable is essentially a Bernoulli Distribution, where $I_A\sim Ber(P(A))$