Office 365: Delivery is made in the form of mail and password information. You can use 5 devices. It provides 1TB OneDrive space for each device. You can use it as an application. You can also use the cloud system via the browser (without an application). Office 2019 and Office 2016: Activation is done with the phone activation process. The code is valid for 1 installation. If you uninstall and reinstall the product, you may need to purchase a new code.