a confusion regarding package updates

[Tapas Mishra]

Hi Alan thanks for your reply.
You correctly guessed it is a server so GUI is not there.
It clears my doubt to some extent.

How ever from man page of apt-get I am not clear with a few things.

On Wed, Jan 19, 2011 at 6:15 PM, Alan Pope <popey at ubuntu.com> wrote:

> The man page for apt-get explains the difference between "upgrade" and
> "dist-upgrade".
Here are the excerpts from apt-get man page

" dist-upgrade
           dist-upgrade in addition to performing the function of
upgrade, also intelligently handles changing dependencies with new
versions of packages; apt-get has a "smart" conflict resolution
system, and it will attempt to upgrade the most important packages at
the expense of less important ones if  necessary. So, dist-upgrade
command may remove some packages. The /etc/apt/sources.list file
contains a list of locations from which to retrieve desired package
files. See also apt_preferences(5) for a mechanism for overriding the
general settings for individual packages."

When it says intelligently handles changing dependencies with new
version of packages then what does it mean?
Is it referring to moving from 10.04 to 10.10?

and from the apt-get man page about upgrade

" upgrade
           upgrade is used to install the newest versions of all
packages currently installed on the system from the sources enumerated
in /etc/apt/sources.list.Packages currently installed with new
versions available are retrieved and upgraded; under no circumstances
are currently installed packages removed,or packages not already
installed retrieved and installed. New versions of currently installed
packages that cannot be upgraded without changing theinstall status of
another package will be left at their current version. An update must
be performed first so that apt-get knows that new versions of packages
are available."

Here my doubt in the above para from man page of apt-get is when it says

"New versions of currently installed packages that cannot be upgraded
without changing the install status of another package will be left at
their current version."

What is install status?

I had a long time back used tasksel on 9.04 to remove a few packages
and it removed everthing on my laptop.
If some thing similar happens I am not in a position to recover back
(in terms of time).
So I am a bit fearing to use apt-get upgrade on the server in question.

-- 
Thanks
Tapas