Definición Conditional probability

Conditional probability describes how likely it is that an event (B) occurs under the condition that another event (A) has already occurred. For example: How probable is it that it will rain in an hour (B) when the sun is currently shining (A)? The conditional probability in this case relates to the calculation of the current weather conditions. It comes to a different conclusion than the calculation of an unconditional probability which does not respect current weather conditions.