>>39442807Gigantamax doesn't change anything besides giving the Pokemon a unique Max Move.
Dynamaxing can be done by any pokemon and raises all their stats for 3 turns while turning their moves into Max Moves based on the type. I may be wrong here but I think the Max Moves are a set base power rather than varying like Z-Moves did. They're also not as strong as Z-moves but they give secondary effects like Max Water causing Rain. Any status move becomes "Max Guard" which is Protect but works on Max Moves (so you can max in repsonse to someone and block their moves).
Some species will get Gigantamax, which is the same as Dynamax but it changes the Pokemon's form as well and lets them use a signature Max Move. For example, instead of Max Water G-Dreadnaw gets Max Stonesurge which is still a strong water hit but instead of rain it's secondary effect is sneaky pebbles.
Only "special pokemon" of the species can Gigantamax and presumably we get those from Max Raids. Not sure if the trait will be breedable from there.
