System occupancy cannot be cleared. This is the size of the iOS system itself, and all programs must rely on this system to run.

iOS is a mobile operating system developed by Apple. Apple first announced this system at the Macworld conference on January 9, 2007. It was originally designed for iPhone, and was later applied to iPod touch and iPad.

iOS, like Apple's macOS operating system, is a Unix-like commercial operating system. Originally this system was called iPhone OS because iPad, iPhone, and iPod touch all use iPhone OS.

So it was announced at WWDC in 2010 that it would be renamed to iOS (iOS is a registered trademark of the network equipment operating system of the American company Cisco, and Apple's name change has been authorized by Cisco).

In January 2016, with the release of iOS 9.2.1, Apple fixed a vulnerability that had existed for 3 years. ?

On September 22, 2018, Apple in the United States secretly added a "trust rating" function based on iPhone users and other device users of the company in its latest operating system.

On November 17, 2021, according to 9to5 Mac, Apple’s iOS 15.2 Beta leaked the new “SportsKit” framework.

Development history:

On January 9, 2007, Apple announced it at the Macworld exhibition. At that time, Jobs called it "iPhone runs OS X". The first version was released in June of the same year. iOS operating system released.

On October 17, 2007, Apple released the first localized iPhone application development kit (SDK), and plans to send it to every developer and developer in February.

On March 6, 2008, Apple released the first beta development kit and renamed "iPhone runs OS X" to "iPhone OS".