Why does vim hide wrapped lines and prints multiple @s?

Question

By default, vim wraps lines but if they are really long, you may end up seeing only @ characters on your screen. What is the name and purpose of this feature?

Answer 1

:help 'display'

    lastline        When included, as much as possible of the last line
                    in a window will be displayed.  When not included, a
                    last line that doesn't fit is replaced with "@" lines.

You can use :set display+=lastline to display as much content as possible in a window