This document provides an overview of the Naive Bayes classifier machine learning algorithm. It begins by introducing Bayesian methods and Bayes' theorem. It then explains the basic probability formulas used in Naive Bayes. The document demonstrates how to calculate the probability that a patient has cancer using Bayes' theorem. It describes how Naive Bayes finds the maximum a posteriori hypothesis and deals with issues like parameter estimation and conditional independence. Finally, it works through an example predicting whether to play tennis using a sample training dataset.