(First off, I'm a bit worried that this might sound like I'm depreciating Android, but I'm absolutely not trying to bash Android, start a flame war or mindlessly praise iOS, because iOS has huge flaws as a mobile OS. I'm a huge fan of Android and to each it's own.)
Apple exerts a lot more control over the entire iOS ecosystem. If you want to use iOS, then you only have one option for a phone: the iPhone. If you want to create iOS apps, then you have to use Apple’s tools and do it Apple’s way. Apple rules with a tight fist.
There are many benefits to this, though
Because Apple knows the exact specifications of every single device that will ever run its operating system, they can make design decisions accordingly. For example, whereas Android needs to support multiple processor types, iOS always runs on ARM-based hardware.
As such, iOS doesn’t need a virtual machine with on-the-fly translation like Android does. All apps are compiled to native code, and that code is executed directly on the hardware. No need for a virtual machine means significantly less RAM used overall.
Furthermore, iOS has a different approach to memory management. Whereas Android memory is handled by the operating system, iOS memory is handled by the apps themselves. Instead of allowing apps to take up as much RAM as they want and freeing it when no longer in use, iOS apps automatically allocate and deallocate memory as needed.
In short, just because iPhones have less RAM doesn’t mean they have worse performance. iOS has a different approach to memory management because it doesn’t rely on a virtual machine like Android does.
