apt-get - install or upgrade packages
install Install packages
# apt-get install package
update Download lists of new/upgradable packages.
upgrade Perform an upgrade.
remove Remove packages.
# apt-get remove package
purge Remove packages includes configuration files.
# apt-get purge package
autoremove Remove automatically all unused packages.
# apt-get autoremove package
dist-upgrade Distribution upgrade.
clean Erase downloaded archive files.
autoclean Erase old downloaded archive files.
download Download the binary package into the current directory.
changelog Download and display the changelog for the given package.

-y Assume "yes" as answer to all prompts.
# apt-get -y install package
-s Perform a simulation of events that would occur based on the current system state but do not actually change the system.
-d Package files are only retrieved, not unpacked or installed.
-q Produces output suitable for logging, omitting progress indicators.
-h Show help.
-V Show full versions for upgraded and installed packages.
-f Attempt to correct a system with broken dependencies in place.
-u Print out a list of all packages that are to be upgraded.