Can I check install and uninstalled packages via terminal?
 

I want to know the version number and package description whether I install a package or not. I rather not install a package just to do this, I just don't want to have to go to the package manager every time Then I want to look up a package.

Well, this is easy, and (welcome to Linux) the better way to manage software. Ubuntu and Debian, eh? Well, use apt-get for that...

Enjoy!!

Thor

in debian you can type dpkg -l 'package-name'.
in redhat type rpm -q 'package-name'.

Well, on Debian based distros it would rather be apt-cache. Use the policy option to get information about available and installed versions and the show option to get a description of a package.
For example:The apt-cache command is also able to show dependencies, reverse dependencies and so on. For more information on the usage of apt-cache just have a look at