First all the pelikula were made sa pamamagitan ng Warner Bros.
But they have diffrent directors.
Batman and Batman Returns were sa pamamagitan ng Tim Burton
link And it the same batsuit in both.
Now, Batman Forever and Batman & Robin were direct sa pamamagitan ng Joel Schumacher
link and produced sa pamamagitan ng Tim Burton
All this pelikula are in the same universe and continuity. The change of batsuits is explained in the movies.
In Batman Forever the riddler destroys the batcave and the equipment, so Batman uses a new bat suit.
In Batman & Robin the change is just an upgrade for the batsuit.
Those changes in stylies were made sa pamamagitan ng the director or pagkuha ng larawan i guess...but also many toys were sold thanks to that.
For madami go to:
link