No lag. The ios system is very smooth.

Basic canshu:

1. Main screen size: 4 inches.

2. Main screen resolution: 1136x640 pixels.

3. Rear camera: 8 million pixels.

4. Front camera: 1.2 million pixels.

5. Battery capacity: 1440mAh.

6. Battery type : Non-removable battery.

7. CPU: Dual-core.

8. Memory: 1GB.

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 use with the iPhone, and was later applied to iPod touch, iPad, Apple TV and other products. iOS, like Apple's Mac OS X 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, it was announced at the 2010 WWDC conference that it would be renamed 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).