K-fold cross-validation is a widely used technique in the machine learning industry to evaluate model performance.
The technique involves dividing the data into k non-overlapping buckets, with each iteration using one bucket as the validation set and the remaining buckets as the training set.
Performance metrics are calculated for each iteration, and various approaches such as mean accuracy and cross-entropy can be used to select the best model.
K-fold cross-validation works for both classification and regression problems.