This menu item by default will attempt to link a track by metadata. If the Settings - Apple Apps - General - Prefer PIDs when Linking option is enabled and the track has a retained PID, the PID will be used for the link attempt. When the option is enabled, this menu item provides the most versatile method of linking.
This menu item by will attempt to link a track by metadata using a track's initial metadata. ie. the metadat when the track was first loaded. This is useful if you've changed the metadata prior to linking.
This menu item by will attempt to link a track by a retained PID. It will only attempt to link files which have a retained PID.
Additional information: