Is there a difference between a hyphen and an underscore?

Question

Search Engine Optimization

Hello, there are a lot of articles on the net on this subject, but they are all from 2008-2010.
If I use transliterated article titles in the URL and replace spaces with underscores _, how critical is this compared to hyphens -?
An example of two links:
site.ru/recept/6528-sup_iz_shchavelya.html
site.ru/recept/6528-sup-iz-shchavelya.html

Answer 1

Not