Basically they are based on the same kernel
but with differences on processor
support,cluster management and memory reqs
due to varied services with each
variation.WIN NT workstation is basically for
the desktop use but with improved stabilityof the NT kernel and better inter-operability
with WIN NT Server and Other variations which
run on the server providing services.Also
server,advanced server and Datacenter server
provide SMP support for thatn 2 processors
and memory support upto 4 GB(DATACENTER
Server).Also there are diffenences on the
number of requests the server OS can handle
at a time with respect to server,advanced and
Datacenter server with datacenter able to
handle around 6000(approx) requests for each
processing thread.You might find the
microsoft web site helpful for Windows
matters and they are likely to know the
most.Alternatively,try out different web
pages such as CNET and ZDNET as they usually
test out new software releases.