In probability theory and statistics, given two jointly distributed random variables X {\displaystyle X} and Y {\displaystyle Y}, the conditional probability distribution of Y {\displaystyle Y} given X {\displaystyle X} is the probability distribution of Y {\displaystyle Y} when X {\displaystyle X} is known to be a particular value; in some cases the conditional probabilities may be expressed as functions containing the unspecified value x {\displaystyle x} of X {\displaystyle X} as a parameter. Wikipedia