DocumentClassifier is a generic, retrainable model for classifying any type of structured or semi-structured documents, building a model from scratch.
This ML Package must be trained. If deployed without training first, deployment fails with an error stating that the model is not trained.

You can train the DocumentUnderstanding model by exporting it from Document Manager to the AI Center session, or by using the Classify option available in Document Understanding.

Once the model is trained, you can use it along with the following activities: Machine Learning Classifier, or Machine Learning Classifier Trainer.