The document discusses Vector Quantized Variational Auto Encoder 2 (VQ-VAE2), a generative model that uses discrete latent representations. VQ-VAE2 builds upon VQ-VAE by introducing hierarchical discrete latent variables to generate high-fidelity images at resolutions up to 1024x1024 in 3 sentences or less. VQ-VAE2 uses a neural network architecture with residual and skip connections, sometimes wi