Which tool is primarily used by data stewards in SAP MDG to manage data?

The Web UI is the primary tool used by data stewards in SAP Master Data Governance (MDG) to manage data. It provides a user-friendly interface where data stewards can easily access, view, and edit master data. The Web UI is designed with functionalities that facilitate data management tasks such as data creation, modification, approval workflows, and validation processes.

This interface allows for a clear visualization of data governance activities and supports efficient collaboration among users. In addition to directly managing master data, the Web UI also provides access to reports and dashboards that help monitor data quality and compliance with governance policies.

While other options such as command line interfaces, desktop applications, and mobile applications may have their uses in specific contexts, they are not the main tools for data management in the SAP MDG environment. The Web UI's tailored features specifically address the needs of data stewards, making it the most effective choice for managing master data.