Lockbackground.tiff

: It uses the TIFF (Tagged Image File Format) extension because it supports lossless compression and high color depth (up to 16-bit), ensuring the background looks sharp even on high-resolution Retina displays. Location

: macOS automatically creates this file by taking your current desktop wallpaper, scaling it to your screen's resolution, and often applying a subtle "frosted glass" blur or darkening effect to ensure login text remains readable. LockBackground.tiff

how do i change my lock screen and wallpaper into 2 different pics : It uses the TIFF (Tagged Image File

In legacy macOS versions, you can typically find it at: /Library/Caches/com.apple.desktop.admin.png (Note: In some versions, it was a .tiff or stored in /Library/Caches/Desktop Pictures/ ). is a system-generated cache file used by older

is a system-generated cache file used by older versions of macOS (typically OS X Lion through macOS High Sierra) to store the image displayed on the login and lock screens. Purpose & Function

In newer versions of macOS (Big Sur and later), this specific .tiff file has largely been replaced by , which is stored within a user-specific UUID folder to support multiple accounts with different wallpapers.

: It serves as the primary visual asset for the lock screen background.