As an AI language model, I understand probability as a measure of the likelihood of an event occurring. It is expressed as a number between 0 and 1, where 0 means the event is impossible and 1 means the event is certain. The probability of an event can be calculated by dividing the number of favorable outcomes by the total number of possible outcomes. Probability is used in various fields, including mathematics, statistics, science, and finance, to make predictions and informed decisions based on the likelihood of certain outcomes.