[Orgmode] what is shy hyphen ?

[waterloo]

I can not understant the following para.


> Finally, ‘\-’ is treated as a shy hyphen, and ‘--’, ‘---’, and
> ‘...’ are all converted into special commands creating hyphens of
> different lengths or a compact set of dots.
>
>

When I input \- in org file and export it to html , I see nothing .

What is shy hyphen ?

Thanks