"Raymond" <> wrote in message
news:AdadnRN2c42g-m7dRVn-...
> What is an intranet? How is it different from the internet?
>
Ah, here's the answer:
The internet is for the most part publicly accessible. It's a bunch of
access points, routers, backbones and more routers that allow computers to
connect with various servers; and in P to P, to each other. The servers
have various things on them, including the World Wide Web, which is a bunch
of websites accessed via the internet; and, also, ftp sites, mail servers,
news servers (housing all this stuff here), and nowadays, collaboration
servers, although these tend to be extranets -

Is it all coming clear?
The "what is" definition is wrong. They are simply defining a network. If
the network were big enough, with enough subnets and routers, you might be
justified in calling it an internetwork.
An intranet is a specific thing: a server (or servers) __within a private
network__ that run what have come to be called web services, which include
web site(s), ftp sites, maybe a company bulletin board or callendar -
although as we know all the big email server manufacturers (eg, msft,
ibm-lotus) are fighting hard to establish themselves as providers of
callendars and "bbs's" or collaboration servers.
BTW if you have a mail server handling the company email, this does not
constitute an intranet. It's just one more server on your network, along
with your file server, your print server, your distribution server,
etcetera. But, add a web server accessible only to your employees and you
have an intranet.
So at it's most basic, an intranet is a web server running a private website
within a private network.
I think someone mentioned that an intranet was like a private internet.
That's a pretty crude description but it's basically true. Here's an
example - say I have a little company with three buildings that have between
them 10 to 12 floors, and everything is networked together.
I do not have an intranet. I have a network. If i am taken by the
ridiculous inflation of language that infects the computer industry, I might
call it a CAN = campus area network. Or if the buildings are scattered
around the country, I might call it a WAN.
I do not have an intranet. I hire you to set up an intranet for me - why?
Because an intranet is browser based, and therefore more comfortable for
people - who will therefore use it much more often to find out what's going
on within the company than they will use, oh, say, a Folder called Company
on the K drive of a server called Zeus. Employees very quickly tire of
looking for the folder called Company on the K drive of Zeus - even in MS
environments, where it is easy.
Unfortunately, I catch on that, until now, you didn't know what an intranet
was, so I withdraw my offer. Now, for home work, it is your job to figure
out and list what you will have to do to set up that intranet within my
private network.
And BTW, as far as an intranet is concerned, access in from or out to the
public internet is completely irrelevant; I already have that set up - or I
ripped it out completely after my sales staff downloaded 400 gigs of games
and music one afternoon.
For an extranet, however, access from outside is usually required, and has
to be set up carefully.
hth
Mike