Batch size has a major impact on the performance of your neural network, influencing the speed, accuracy, and generalization of your network. A larger batch size can reduce training time by exploiting parallelism of modern hardware, such as GPUs and TPUs. However, it can also cause memory issues and slow down communication between devices. On the other hand, a smaller batch size can improve accuracy by introducing more stochasticity and diversity in the training process. But, it can also lead to underfitting and poor convergence if the batch size is too small. Finally, a moderate batch size can enhance generalization by providing a balance between exploration and exploitation, as well as reducing the gap between the training and validation distributions. But, an extreme batch size can degrade generalization by causing either overfitting or underfitting.