OneDrive is a Microsoft service that offers storage for files in the "cloud". OneDrive offers 5GB of storage space for free. You can simply sync, store, and share all types of files to other people and devices. Files stored in OneDrive can be accessed with any device connected to the internet or from the application on your tablet. You can have all your web-based files stored on your tablet because OneDrive syncs the folders.
This Microsoft video provides a quick explanation of what OneDrive is and the benefits of using it: