Updating unlocked iphone software
IPSW stands rather simply for i OS Software, and IPSW files are basically just individual firmware downloads for specific i OS devices.
Though the average user is better off going the easy routes of updating i OS with i Tunes or OTA, IPSW can have very practical uses as well.
A significant advantage to using firmware files can be found for users with limited access to broadband internet, where downloading a software update on a remote faster connection makes more sense.
Typically you would then copy that IPSW file to a USB key or DVD to bring it home to manually update a device.
Also, for users with many of the same i OS devices, having a single IPSW downloads let’s you conserve bandwidth by applying a single update to many devices.
Rarely, firmware files are required to restore a malfunctioning i Phone, i Pad, or i Pod touch that is basically bricked, but still functional.
This is somewhat rare, but if an i OS update is interrupted it can happen, which usually requires a device be placed into DFU mode and restored manually with firmware.