Forgot . .. gypsum will also bind "sodium" chloride salts!

Sorry, I don't quite understand the significance of using gypsum to
bind sodium chloride salts. I assume this is a good thing, not a bad
thing. I assume the salts are from over-fertilizing the soil, and the
use of gypsum is a way to remove the salts. Is my understanding
correct?

Thanks for any following up info on this issue.

Jay Chan