What is the difference between "Masos, Osos, Mofsim and Milchamah"?
Rashi: "Masos" are 'tests', 1 where Hashem displayed His capability; 2 "Osos" are signs, to prove that Moshe was Hashem's Shali'ach 3 : "Mofsim" are wonders (or miracles), such as the ten Makos, whereas "Milchamah" refers exclusively to destruction of the Egyptians at the Yam-Suf. 4
And what is their significance?
Seforno: They serve as proof that all that happened to the Egyptians did not happen by chance, but by the specific Will of Hakadosh-Baruch-Hu.
And what are the connotations of "bi'Zero'a Netuyah"?