Linux Answers

What is the advantage of using sudo apt-get autoremove over a cleaner app?

https://askubuntu.com/questions/527410/what-is-the-advantage-of-using-sudo-apt-get-autoremove-over-a-cleaner-app
Whenever you install an application (using apt-get) the system will also install the software that this application depends on. It is common in Ubuntu/Linux that applications share the same libraries. When you remove the application the dependency will stay on your system.
So apt-get autoremove will remove those dependencies that were installed with applications and are no longer used by anything else on the system.

apt and apt-get

https://askubuntu.com/questions/445384/what-is-the-difference-between-apt-and-apt-get

https://unix.stackexchange.com/questions/159094/how-to-install-a-deb-file-by-dpkg-i-or-by-apt