I think the equivalent is the test set. A test set is used to evaluate the performance of the model, after all the tinkering. As such, you need to take great

I think the equivalent is the test set. A test set is used to evaluate the performance of the model, after all the tinkering. As such, you need to take great care to make sure that you don't have train-test leakage (e.g. taking a random sample for stock market prediction when you need to do a time-based split), or that you don't use the test set more than once (e.g. choosing the best model based on the test set).