iPad Apps Support Multiple Form Factors

iPad apps are developed using a technology called size classes. This ensures an iPad app supports multiple form factors, such as full screen or split view. Stage manager takes all of these existing size classes and uses them as predetermined sizes in practice. When you go in with your finger or with the pointer and resize a window in stage manager, you're not resizing it pixel by pixel like on a Mac. That's like an invisible slider, basically,. that controls these multiple sizes that you have - but it's not real Mac like resizing.