What is the definition of "Masos"?
Rashi #2: "Masos" is synonymous with 'Nisyonos' (tests).
Targum Onkelos and Targum Yonasan: "Masos" is synonymous with 'miracles'.
What is the difference between "Osos and Mofsim"?
Rashi: "Osos" are signs, to prove that Moshe was Hashem's Shali'ach. "Mofsim" are wonders (or miracles), such as the ten Makos.
What are "Yad Chazakah" and "Zero'a Netuyah" referring to?
Rashi: "Yad Chazakah" refers to the Makah of Dever (pestilence), and "Zero'a Netuyah", to the sword of Makas Bechoros. 1
See Sh'mos 9:3.
What is the significance of the five things listed here "ha'Masos ... ", "ha'Osos", "ha'Mofsim", "ha'Yad ha'Gedolah" and "ha'Zero'a ha'Netutah"?
Oznayim la'Torah: They hint at the ten Makos - since each item hints at two Makos. 1
As the Ba'al ha'Gadah teaches us.
QUESTIONS ON RASHI
Rashi writes that "Zero'a Netuyah" refers to the sword of Makas Bechoros. What was that?
Sifsei Chachamim #1 (citing 'Yesh Omrim): It refers to the sword of Hakadosh-Baruch-Hu, with which He slayed the firstborn.
Sifsei Chachamim #2 (citing the Chizkuni) and Bartenura: When Moshe announced Makas Bechoros, the Bechoros demanded that Par'oh release Yisrael; when he refused, they made war with the other Egyptians were killed. 1
We learn this via a Gezeirah Shavah Netuyah from "ve'Charbo Shelufah be'Yado Netuyah al Yerushalayim" - in Divrei ha'Yamim 1, 21:16.