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- It is the session used when the 'Auto-Connect' option is turned on (found under Options/Application)
This option allows you to automatically connect whenever the program is started, but it will always connect to the same host (the one specified in the default session). A better way would be to create one or more shortcuts on your desktop specifying a session (see command line parameters). - It is used as a template for new sessions (options you don't specify will have the default session's setting).
Here is an example:
Let's say you have two sessions defined, one named 'Work', the other named 'Play'. If you change the text colour for protected fields for session 'Work', only that session will show the change; 'Play', as well as any new sessions you define at a later time, will continue to use the original colour. If you change the same option for the default session, both 'Work' and 'Play' will continue to use the original colour, but all new sessions defined from now on will use the new colour.
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