sudo apt-get update # update the Repository List's
sudo apt-get install vlc # Install the package
sudo apt-get -d install vlc # Download the package and kept in /var/cache/apt/archives. this wont get install
sudo apt-get upgrade # check updates for installed package
sudo apt-get dist-upgrade # updated the entire system
sudo apt-get autoclean # Remove the packages no longer installed
sudo apt-get clean # Remove all cached pakages from /var/cache/apt/archives to free disk space
sudo apt-get --purge remove vlc # Remove the package and its configuration file's
sudo apt-get -f install vlc # Tries to fix any unmetdependency message'e while install
sudo apt-key list # Display the gpg keys that APT knows
apt-cache search vlc # Search the package database
apt-config -v # Information about Current APT utility
apt-cache show # shows the package information
apt-cache stats # Print statistics on all packages installed
apt-cache depends # Print Dependencies for a package, Installed or not
apt-cache pkgnames # List all packages installed in the system