is near one representing a high probability that the input was real rather than fake but half the time we also apply the discriminator to examples that are in fact fake in this case we begin by sampling the latent vector Z in this case we sample Z from the prior distribution over latent variables so Z is essentially a vector of unstructured noise it's a source of randomness that allows the generator to output a wide variety of different vectors we then apply the generator to the input vector Z the generator function is a differentiable function