The Naive Bayes algorithm is a classification technique based on Bayes Theorem. It assumes that the presence of a feature in a class is unrelated to the presence on any other feature. The algorithm rely on the posterior probability of the class given a predictor, as we can see in the following formula:
where:
P(c|x) - the posterior probability of class given a predictor
P(x|c) - the probability of the predictor
Find here the blog post for a better understanding.