cuDNN (CUDA Deep Neural Network library)
cuDNN (CUDA Deep Neural Network library) is NVIDIA’s library of highly optimized GPU kernels for operations that dominate deep learning: convolutions, matrix multiplies used in attention, pooling, normalization (batch/layer), activations, and recurrent cells. Its objective is to deliver near-peak performance on CUDA-capable GPUs without every framework author hand-writing assembly-tuned kernels. PyTorch, TensorFlow, and many inference engines call cuDNN (directly or via cuBLAS) under the hood for training and serving. cuDNN sits between raw CUDA and application code; version alignment with the CUDA toolkit and driver is mandatory for supported deployments.