Shotwell supports multiple libraries on the same computer with the concept of profiles. A profile is a set of meta-data and settings associated with a library folder.
All profiles are completely isolated from each other. While it is possible to use the same library folder for different profiles, it is not recommended.
Profiles can either be created using the dedicated Shotwell Profile Manager, calling shotwell --profile-browser from the command line or the Profiles section of the settings Edit ▸ Preferences
Selecting a profile
A profile can only be selected during start-up and cannot be switched during run-time.
To select a profile, start the Shotwell Profile Manager and select a profile using double-click, or calling shotwell --profile name