This function allows you to set up an app without master data. In the section Master data of the setup wizard, you can select the option 'do not use master data'. Additionally, you can turn the feature on or off at any time in the Platform Settings tab of 'Administration'.
Don't worry. If you change this setting, no master data will be deleted, only the view in 'Master data' will be optimized. This is mainly useful for smaller apps with few units, as it simplifies the setup of your app as well as the view of your master data.
However, please note that apps without a master data structure will not be able to channel micro apps and their content.