In probability theory, an event represents a subset of the underlying sample space. When working with a random variable $X$, an occurrence where the variable takes on a specific value $v$ (denoted by $X=v$) or falls within a specific range of values (such as $1 \leq X \leq 3$) is considered an event. A probability score, denoted like $P(X=v)$ or $P(1 \leq X \leq 3)$, is assigned to these events to represent their likelihood.