Linux uses virtual desktops to spread your work out. How you use them is up
to you. This is an alternative to Windows method of minimizing applications
to the taskbar. You can have any number of them. I have 36 in KDE in use.
Most people are happy with four.
Depending on the desktop environment you set them up differently. Older
versions of Ubuntu have two panels with the workspace switcher on the bottom
right. The last version has a launcher to the left with the workspace
switcher at the end.

If you have Compiz enabled you can have a 3D rotating cube. No end to the
fun.

I'm being reminded of why I left work places and multiple desktops alone in the
past. Before I opened the switcher I had a few text files on my desktop. I
clicked the switcher and it open all four. So then I clicked one and deleted one
of the files. When but that removed the same file from all four. That seems to
suggest that they will all be the same. What good is that?

This is the strangest happening I have ever heard of.
In my case, multiple workspaces are the best thing that Linux GUIs offer. It
eases work considerably. Compiz also has some helping features that are
extremely well done. If you have many windows open that can save you a lot of
work and trouble because it is easy to see which thing where is.

Files and programs can be either visible on all work spaces or only
visible on one workspace. In terms of working with multiple programs
and files then having them only visible on the one work space is the
most convenient but sometimes it's useful to have something visible on
all work spaces ( i.e. a text file for copy / paste operations between
multiple open files ). In general, it's less confusing to have a file
or program only visible on the work space it was launched in.

Not had much success getting work spaces working as I'd like in Unity
and tried the 11.10 Beta 2 in VBox but although it installed and ran
OK the graphics quickly screwed up big time - going to give it another
go with the 32bit version to see if that works any better. 11.04 in
VBox doesn't allow Unity

That is why I have never used the feature, what good is it if all workplaces are
the same?

The whole point of work spaces is that they *don't* all have the same
content - each work space is dedicated to one program. Case in point
in this new install of Ubuntu I have here - work spaces have gone awry
so everything is as Windows would do it, every program running in the
same window. Whilst getting e-mail and browsing the web I've been
doing some batch processing with Audacity and every new file loaded /
saved the Audacity window pops to the front and overlays what I want
to be doing whilst it is processing - damned annoying !!

With work spaces operational I would have had Audacity running in it's
own work space where it would not have interfered with other work
spaces running E-mail or browser.

I really do have to get this Ubuntu install sorted - once you've
worked with multiple work spaces it really is the most sensible way of
running many tasks at the same time Think I've messed up big
time with this install and will need to start from scratch again !

The workspaces are all the same in what you /can/ do, but not in what in
you /are/ doing at any one time.

So for instance in any workspace you can run LibreOffice, and in any
workspace you can use it to edit a file called MyDoc.odt, and in any
workspace you can use it to edit a file called OtherDoc.odt.

If you want both documents open at the same time, without workspaces (as
in Windows) you open them both, and minimise one to the taskbar while
you are working on the other. With workspaces, you can open MyDoc in one
workspace, and OtherDoc in another workspace. It's just a somewhat
different way of organising the work you are doing at any one time.

That's the be all and end all of workspaces, as I understand them.

Not sure if you ever got this resolved... the difference that I think
you were missing is you can have different programs *running* in
different workplaces, but not different files/icons displayed on the
workspaces. The different running programs on each workspace allows
you to group your activities as you describe in your opening post.
There have traditionally been ways to launch certain programs in
certain workspaces, or you can switch to a given workspace and launch
a program in it. At least in Gnome 2.X (Ubuntu 11.04-classic and
below), the files (icons) displayed on all workspaces are tied to the
folder "Desktop" and there is no way to change that. Any
files/shortcuts saved onto one workspace will appear in all
workspaces. So you see the same icons on each desktop as the intended
behaviour. You can read some of the rationale for this on
launchpad.net (it's been a while ago, but I remember it was discussed.
It would take some digging to find it) I believe KDE offers
desktop-specific activities that can do what I think you are looking
for (i.e., have specific files and shortcuts displayed on different
workspaces). I have never liked the way they implement it, though.
Gnome 3.X and Unity also offer some different ways of grouping
launcher activities that you may enjoy reading about.