• sudo apt-get update: Updates the package lists for upgrades and new installations.
• sudo apt-get upgrade -y: Upgrades all installed software to the latest version without asking for confirmation.
• sudo apt-get autoremove: Removes packages that were automatically installed but are no longer required.
• sudo apt-get autoclean: Removes unnecessary packages and files from the package cache.
• sudo apt-get clean: Deletes all packages from the package cache.
• sudo journalctl --rotate: Rotates and archives the journal files.
• sudo journalctl --vacuum-time 1d: Clears all log files older than 1 day.
• sudo rm -rf ~/.cache/thumbnails/*: Removes thumbnail cache files

After these system maintenance tasks, there's another script section that deals with removing old revisions of snaps:

It sets the script to exit if any command fails (set -eu) and specifies the language as English (LANG=C).

snap list --all | awk '/disabled/{print $1, $3}' lists all installed snaps that are disabled and extracts the snap name and revision number.

It then loops through the list of disabled snaps, removing them one by one using snap remove.

Finally, it sends a desktop notification using notify-send to indicate that the cleaning is done.