# What is Bayes' theorem and error?

What is Bayes' theorem and Bayes' error?

• Recently, this question was categorized as a low quality post by the SE.AI system. On the first look, the OP likes to know what Bayes' theorem is. But he isn't asking for the definition from Wikipedia, but he would likes to know, how to use Bayes theorem in context of solving AI problems, for example in the domain of decision trees. With the help of machine learning it allows to repeat an experiment very often which is using current GPU hardware in an optimal way. – Manuel Rodriguez Sep 1 at 14:50

$$P(A \mid B) = \frac{P(B \mid A) P(A)}{P(B)}$$