The character "
seems to produce the right quotes, but this is not really true. There are two cases.
OT1 encoding
Look at what happens with these apparently identical inputs:
\documentclass{article}
\begin{document}
this ends a quotation." And here text starts again
this ends a quotation.'' And here text starts again
\end{document}

Can you spot the difference? In the first case a normal interword space is produced after the quotes, in the second case there's an extended space, which is what's expected after a period (preceding or not the quotes), of course assuming "non French spacing".
T1 encoding
Add \usepackage[T1]{fontenc}
to the input above and you get

The problem with the extended space seems to have disappeared, but this is not true: the fact is that the glyph produced by "
is wider than the curly double quotes. But it's even worse than before, because now the quotes are straight and not curly, which is unacceptable from a typographycal point of view.
Conclusion
All tutorials recommend ''
for producing closing double quotes and they are fully right.
\usepackage[T1]{fontenc}
so it is not recommended.”
will work if you use the correct inputenc option.''
and they are right. Inputting"
has unpredictable output.