How to unpack deb files from terminal for Debian/Ubuntu Linux

I got a file named filename.deb. Is it possible to unpack this .deb file from terminal? Further how can I install filename.deb file on a Debian Linux desktop?

Hi,

Use this dpkg command to install deb file from the terminal:

dpkg -i filename.deb

To see the content of deb file:

dpkg --contents filename.deb