The parts of a ScrolledList widget visible to the user are:
A Tkinter Listbox widget that displays
the lines of text.
An optional vertical Scrollbar widget
that allows the user to scroll up and down through the
lines of text.
An optional horizontal Scrollbar that
allows the user to shift the text in the Listbox to the left or right when the lines
are too long to fit in the window.
Here is a diagram showing the layout of these components in the most general case, with both vertical and horizontal scrollbars:
