How is the Save method different from ResetUndoInfo method in the WinForms SyntaxEditor (EditControl)?
Reset undo info method
The Save and ResetUndoInfo methods do the same function in most scenarios when a pre-existing file is being used in the EditControl. The ResetUndoInfo method introduces a "save point" like functionality, and all the contents up to that point gets saved and cannot be undone, while the Save method simply saves the contents into the currently open file.
But consider a scenario where some text is being typed into the EditControl without having opened a pre-existing file in it. Try to undo the text typed and it works correctly as expected. Now type something into the EditControl and invoke ResetUndoInfo so that a save point is inserted. Note that no file is being created and nothing is saved in a file at this point. Try to undo this and nothing happens. This is where ResetUndoInfo method differs from Save method.
Reference link: https://help.syncfusion.com/windowsforms/syntaxeditor/editing#reset-undo-redo-buffer