Probability is a measure of how likely an event is to occur, expressed as a fraction between 0 and 1. Examples of events where probability can be calculated include outcomes of coin tosses, dice rolls, and draws from collections like cards. Specific probabilities can be found for scenarios like the likelihood of rolling a multiple of 3 on a single die, obtaining a total over 7 from two dice, drawing balls of the same color from a bag, or selecting cards that are both black or both queens from a deck.