If you are currently recording a tracklog of where your GPS device has been, the Clear Tracklog command will clear whatever is currently recorded that has not yet been saved using the Save Tracklog command.
The Record Tracklog command controls whether or not a bread-crumb trail (i.e. tracklog) will be recorded to log where the GPS device has traveled. This tracklog can be saved to any of the supported vector export formats. The drawing style of the tracklog can be configured on the Line Styles tab of the Configuration dialog.
The Save Tracklog command will save the currently record tracklog to a permanent line feature. When selected, this command will display a dialog allowing you to specify any additional desired attributes and/or drawing styles that you would like to associate with the tracklog. In addition, any extraneous points that do not contribute to the shape of the tracklog will be automatically removed to save space.
Any saved tracklog features will be added to the user features layer, which appears in the Overlay Control Center. The saved tracklog features can be exported to any of the supported vector export formats
The Simplify (Reduce) Tracklogs when Saved command controls whether or not recording GPS track logs are simplified (reduced) when saved or whether all recorded points are kept. If this option is checked, any points which do not significantly contribute to the shape of the recorded track log will be removed to conserve memory.