does postgresql works on distributed systems?

Hi,

          My question is

        Microsoft sql server 2005
cannot be shared on multiple systems i,e in a network environment when
it is installed in one system it cannot be accessed one other
systems.One can access only from a system where it is already installed
but not on the system where there is no sqlserver.Is postgresql similar
to sql server or does it supports network sharing i,e one one can
access postgresql from any system irrespective on which system it is
installed.

         If there is any
weblink for this kindly provide that also.

    Thank You,

     Avinash