What does “Overfitting” mean?

How well a model performs on new, unseen data outside the training set.

When benchmark test examples or close variants are present in training data, inflating reported performance.

Training approaches that let a model keep learning from new data without forgetting prior knowledge.

Techniques that create modified training examples to improve model generalization.

Continuing training on domain-specific data to adapt a pre-trained model to a specific task.

The latest point in time reflected in a model's training data.