Default Shadow Mode:

1 Way Backup will shadow files from your Shadow Set to the backup device which can be a server, a PD/CD ROM or other optical drive or a Zip drive etc.

2 Way Transfer will co-ordinate both sets of files allowing you to work on the server files or the notebook files as you wish.  SolarSys Notebook Shadow will then copy the latest version over the earlier as appropriate.

2 Way Briefcase is similar to 2Way Transfer except that only files on the source PC are considered for the 2 way process.  This enables you to have a large number of files on the server and have a smaller subset of "live" files on the notebook.  Any new files created on the notebook will be copied to the server but new files created on the server will not be transferred back.

The default shadow mode can be overriden on specific Shadow Spec lines using the /backup /2way and /briefcase switches.

1 Way Backup Queries:
If you use 1 Way Backup mode then you will get a query if the Source file being backed up is older than the previously backed up Shadow file.  This is because the Shadow file has been changed in some way and Notebook Shadow will not automatically over write it with an older source file.  To agressively overwrite the newer shadow file then check the query's checkbox and re-run.  If you realise that you have accidentally changed the Shadow instead of the Source then 
either:
Check the 2 Way Briefcase Shadow Mode radio button, allow Notebook Shadow to run once then re-check the 1 Way Backup Shadow Mode radio button.
or:
Double click the query then when the details dialog appears, use the Aggressive "Reverse Shadow" facility.