Overfitting in neural networks occurs when models become too specific to training data, failing to generalize. This is caused by excessive model complexity relative to data size. Detect overfitting by monitoring training and validation set loss/accuracy; divergence signals overfitting. Solutions include: gathering more data, using smaller networks, early stopping, dropout (randomly ignoring neurons during training), and weight regularization (penalizing large weights). This segment defines overfitting as a model becoming too specific to its training data and failing to generalize to new data. It explains that the primary cause is a model having too much freedom in its parameters relative to the amount of training data, making models with high degrees of freedom or small training sets most prone to overfitting. This segment discusses strategies to address overfitting. It highlights the importance of having sufficient training data and suggests obtaining more data or using techniques like data augmentation or transfer learning if data is limited. If increasing data isn't feasible, it recommends scaling down the model size to reduce parameter freedom. The video emphasizes the importance of using validation sets to detect overfitting. It explains how to monitor training and validation set loss and accuracy to identify discrepancies that signal overfitting. A key indicator is when validation set loss increases while training set loss continues to decrease.