Comment # 6 on bug 1210148 from Michael Andres

(In reply to Grzegorz Wo������ from comment #4)
> Probably. I have read the manual for both commands, but it is still unclear
> which one does what. 

Maybe this helps:

  Somepackage
    provides: wrzlprmpf 

  Foo:
    requires: Somepackage

  Baa:
    requires: wrzlprmpf


# zypper se --requires  Somepackage
Finds 'Foo' because it (literally) requires 'Somepackage'.

# zypper se --requires-pkg  Somepackage
Finds 'Foo' and 'Baa' because both require something
the 'package Somepackage' provides.