modalPresentationStyle is a property of UIViewController in iOS. It determines how a presented view controller shows and transitions in UIKit.
.fullScreen presents the view controller over the entire view of the window including the screens edges. One thing to note here is that if the view that is presented has transparency it will see black. This is because once the presented view finishes animating the views it is presented on are removed from the screen.
.overFullScreen does the same thing as .fullScreen except the view being presented on is not removed from the screen. This is good if you are presenting a view with transparency as the screens below this view will still be seen under the transparent components (for instance if you wanted to apply a blur to the background of an alert)
