Is there any deeper difference between Helvetica Neue and Helvetica Neue Cyr?

Question

css

Is there any deeper difference between Helvetica Neue and Helvetica Neue Cyr than the name?
If there is no difference, then why such a division of fonts and how to correctly compose the font-family rule (it means the case if the font is already installed by the user, as an alternative would be "Arial, Helvetica, sans-serif")?
At the moment I have this:

HelveticaNeue", "Helvetica Neue", Helvetica, Arial, sans-serif

Duplicate by adding Cyr?

Answer 1

Most likely "Helvetica Neue Cyr" has in its subset not only glyphs for Latin, but also glyphs for Cyrillic. The division exists to reduce volume when Cyrillic is not needed.
Therefore, "Helvetica Neue" may not be included at all. Or don't include "Helvetica Neue Cyr" if you only have Latin.