What is a neural network?

A neural network is a computational model loosely inspired by the structure of biological brains. It consists of layers of interconnected nodes (neurons): an input layer, one or more hidden layers, and an output layer. Each connection has a weight, and each neuron applies an activation function to its weighted inputs. During training, weights are adjusted via backpropagation to minimize prediction error. Neural networks can learn complex non-linear patterns and are the foundation of deep learning.