Stage Manager was an iPadOS 16 feature that was announced during the WWDC 2022 event, but it’s only limited to iPads with the M1 chip.
Stage Manager allows users to resize their apps on windows for better multitasking, as well as connect to an external display to manage up to 8 apps in total. However, those who wish to get this feature will either have to have an M1 iPad or upgrade to one.
Apple recently gave an explanation as to why this is the case. Apparently, Stage Manager requires ‘fast storage, flexible display I/O and a large internal memory’, all of which the M1 chip does. The M1 iPad Pro, for example, has 16GB of RAM and faster storage compared to its predecessor.
In general, iPadOS 16 is available to all iPad pros, the 5th gen iPad, the 5th gen iPad mini and newer, and the 3rd gen iPad Air and newer. A public beta may be released this July and available to all in September.