apt-get basic options

apt-get - Package management (like yum) via apt-get runs hand-in-hand with the /etc/apt/sources.list file.

dpkg - is a tool to install, build, remove and manage Debian packages(like rpm).

List packages - apt-cache pkgnames
Search for a package - apt-cache search vsftpd
Find all packages starting with ‘vsftpd‘-   -apt-cache pkgnames vsftpd
Check Package Information - apt-cache show netcat

Update System Packages -  sudo apt-get update
he ‘update‘ command is used to resynchronize the package index files from the their sources specified in /etc/apt/sources.list file. The update command fetched the packages from their locations and update the packages to newer version.


Upgrade Software Packages - sudo apt-get upgrade

The ‘upgrade‘ command is used to upgrade all the currently installed software packages on the system. Under any circumstances currently installed packages are not removed or packages which are not already installed neither retrieved and installed to satisfy upgrade dependencies.

More: http://www.tecmint.com/useful-basic-commands-of-apt-get-and-apt-cache-for-package-management/