Final answer:
Cost-complexity pruning is a technique used by CART algorithm to simplify decision trees by reducing their complexity. It helps to prevent overfitting and improves the tree's generalization ability.
Step-by-step explanation:
Cost-complexity pruning is a technique used by CART (Classification and Regression Trees) algorithm to simplify decision trees by reducing their complexity. It involves iteratively removing branches or nodes from the tree based on a cost-complexity measure. The trade-off of cost-complexity pruning is that it can lead to a reduction in the accuracy of the tree's predictions, but it helps to prevent overfitting and improves the tree's generalization ability.