This feature allows user to select default Photoshop version which would be launched for Photoshop specific workflows (Place in, Tools menu) from Bridge.
If a user has multiple versions of Photoshop installed, they can select a specific version from Preferences > Applications to execute Tools/Place-in operations.
Note: These preference changes will not affect the Open and Open With operations. They will continue to be associated with the default file type associations (FTA).