Sessions allow you to group your watermark and profile settings in to one file. You may have one or more different watermarks that each get saved to a different destination. You can define your watermark and image sources and save them ready for use next time in to a .123W file.
When you start-up 123 Watermark, the application will load your last saved session.
You can save your current session by going to the File menu and clicking Save Session or Save Session As...
There is also a Recent menu which will lists your most recent sessions for easy access.