Gundam is the titular mobile suit of Mobile Suit Gundam. The Gundam was incredibly advanced for its time. Built from lightweight Luna Titanium Alloy, its frame was both lighter than that of Zeon's mass-produced mobile suits and much sturdier, able to shrug off a Zaku II's machine gun fire with little to no damage. Its offensize power was above and beyond that of the Zeon Zakus.
The successor to the first fielded mobile suit, the Zaku II improved on everything the previous model offered. It was faster, far more durable, had a better Minovsky Reactor, and could be fitted with far more weapons. The Zaku II was the mainstay of the Zeon military for most of the One Year War.
Z'Gok is a mass production amphibious mobile suit. Z'Gok was very agile and fast in and out of water. MIP also replaced the bulky ballast water tanks used by the Gogg and Acguy for cooling off the mobile suit for out of water operations with an air cooling fan system. Notably, the weapon layouts were improved.