As you see in the above example, In and In looks just the same, but the outputs are different.
The fact is that there is no linebreak symbol in In, but there is one linebreak symbol in In.
(There is a linebreak between Goto["End"] and Label["End"] in In.)
The above example was screen-shoted when mathematica notebook width was decreased with a setting 'format - word wrapping - wrap at windows width'.
So the linebreak in In is completely unnoticeable.
In text editor like notepad++, there is an option to view line break symbols. Is there a such option for mathematica?