Firmware

A firmware is an IPSW file that contains everything needed to run the core operating system, iOS. Beta firmwares have also been released, but require an Apple Developer account to acquire. To check for updates, iTunes contacts ax.phobos.apple.com.edgesuite.net.

Firmware List (by device)

 * Apple TV
 * Apple Watch
 * iPad
 * iPad mini
 * iPhone
 * iPod touch