Which installation type is used to maintain existing applications and data while upgrading an OS?

The in-place upgrade is the installation type that allows users to upgrade their operating system while preserving existing applications, settings, and data. This process maintains the user's installed programs and personal files, making it a convenient option for those who do not want to lose their custom configurations or reinstall all applications after an OS upgrade.

During an in-place upgrade, the new operating system is installed over the existing one, which can streamline the upgrade process and minimize downtime since the user does not have to set everything up from scratch. This option is particularly beneficial for users in a production environment or for those who depend on specific software configurations.

In contrast, a clean install would erase all existing data and applications, while a repair installation typically addresses problems with the OS but may not always preserve user-installed applications or data as effectively as an in-place upgrade. Image deployment involves deploying a pre-configured image to systems, which does not also preserve existing applications or data in the same manner as an in-place upgrade does.