How to install updates via command line?

When I log into my web server via SSH I see the information:

88 packages can be updated.
80 updates are security updates

I tried apt-get update then apt-get upgrade but each time I log in I still see the message about updates. How do I install them?

Try this:

sudo apt-get update        # Fetches the list of available updates
sudo apt-get upgrade       # Strictly upgrades the current packages
sudo apt-get dist-upgrade  # Installs updates (new ones)