[TYPO3] one backend, multiple Frontends

[neugi]

Hi,

i'm trying a new project and searching for a cms system that will do the
job.

here is my problem:

i want to have a one backend for about 4 websites on 4 differnet domains
with different content.

some parts on the 4 websites will be shared eg calendar.

is this possible with typo3? how to handle uploaded files, is there a way to
only show content on on site, oder an multiple site at the time of creation?
or do i have to copy the content several times?

my problem is that the people which will take car about the system don't
understand anything from ftp or programming and they want to have the system
as easy as possible. so there is no way to tell them to transfert eg
pictures from on server to a nother.

maybe somebody knows a solution on this, or a hint where to look for a
solution for this.

best

PS otherwise i've to write a own CMS ;)