The chance of hitting a given spot on a darts target board is zero. Modelling the probability therefore uses regions on the darts board.

Probability theory is the part of mathematics that studies random situations. Probability theory usually studies random events, random variables, stochastic processes, and non-deterministic events (events that do not follow a simple pattern).

Tossing a coin, winning the lottery, or rolling a die are random events. However, random events have certain patterns, which can be studied and predicted, using probability theory.