What are virtual packages in Linux?

Question

I am trying to run some example libreoffice python scripts and getting errors.

Google suggests that one possible reason is that libreoffice-script-provider-python is not installed. It is not listed in Synaptic. This page virtual package says that it is a virtual package provided by python-uno. Does this mean?

Answer 1

A 'virtual package' is a package that does not install any files itself, but instead is dependent on some related 'set' of packages. That is, when you install it, apt-get (or aptitude) installs a group of packages. It is a convience hack. Rather than tell people:

apt-get install foo bar baz whatever mumble liba libb libq

you can instead tell people:

apt-get install interesting-package

'interesting-pacakge' lists foo, bar, baz, whatever, mumble, liba, libb, and libq as packages it depends on.