Now, if your null hypothesis is true and you fail to reject it, well, that's good. This, we could write this as, this is a correct, correct conclusion. The good thing just happened to happen this time. Now, if your null hypothesis is false and you reject it, that's also good. That is the correct, correct conclusion. But if your null hypothesis is false and you fail to reject it, well, then that is a type two error. That is a type two error.