Blinking question mark ion restart

A Mac does not run iOS. Only mobile devices can run iOS. A Mac runs macOS.

The blinking question mark at startup usually indicates that the Mac is unable to find the files needed to boot the Mac.

Without a backup, you will probably lose everything.

Hi thaihok,

A flashing folder with a question mark indicates that your Mac couldn't find the default startup disk at boot time. This is usually either a small error or a very serious one. It could either indicate that your Mac forgot where to boot from, or that your internal drive is dead.

One way to test whether your internal drive is really dead is to boot Recovery Mode on your Mac. Hold down Command-R as you turn on or restart your Mac. If you immediately see the Apple logo, it's a sign that your Mac was able to boot Recovery Mode straight off of your internal drive. However, if you see a spinning globe instead, your Mac couldn't locate Recovery Mode on your internal drive and had to resort to booting Recovery Mode over the Internet.

Once inside Recovery Mode, open Disk Utility and run First Aid on your startup disk.