https://wccftech.com/macos-big-sur-will-install-software-updates-faster-than-ever/

macOS Big Sur, Apple's latest major update for its desktop operating system, will feature faster software updates in the future thanks to background installation.

macOS already supports download software updates in the background, however, installation is a different story. When the update is downloaded, the installation process starts afterward and requires a few reboots to complete. Apple has finally improved this process by enabling updates to install in the background.