What is the purpose of the Cache folder in the DU framework?

The Cache folder in the DU (Document Understanding) framework is designed to hold the expected results for each test. This includes processed documents and their corresponding annotations that are used to validate and benchmark the performance of the machine learning models. When training or evaluating the models, having a clear set of expected results is essential to ensure accuracy and reliability in the system's predictions. The Cache folder thus plays a critical role in facilitating structured testing and enhancing the efficacy of model training by providing a reference point against which actual results can be compared.

The other options, while relevant to data handling and processing, do not accurately describe the specific function of the Cache folder in the context of the DU framework. The storage of documentation for machine learning purposes or archiving old learning data does not align with its primary role, nor does it function as a backup for all processed documents, which is a more general data management process.