file.nb is a Mathematica notebook file.
DefaultFormatType is an option for cells that specifies the format used for displaying expressions in a newly created cell.
WidgetGroup[{content, ...}] specifies custom layout settings for how the content widgets are displayed.
ExampleData["type"] gives a list of names of examples of the specified type.ExampleData[{" type", " name"}] gives the default form of the named example of the specified ...
"StyleOther" is a front end token that opens the Custom Style dialog.
File Path opens a dialog to select and paste the full pathname of a file into the text at the insertion point.
Show Ruler toggles ruler display along the top of a notebook.
InputPacket[] is a MathLink packet that indicates a prompt for input as generated by Input.
InputStringPacket[] is a MathLink packet that requests input in string form.
FrontEndExecute[expr] sends expr to be executed by the Mathematica front end.