Docs: Lack of OpenStack storage concepts explanation

The problem:
I'm new to OpenStack and while learning it, many of it's concepts seem alien.

I did read start guide PDF (Nova), the Install Guide (Nova) and parts of the Admin Guide (Nova).
 (from docs.openstack.org), but it doesn't explain the most basic concepts.

Things like:
1. Object Storage (swift) vs. Network File System (NFS)
=============================================
Why SWIFT ?

According to: "notmyname"
<notmyname> technologov: the things that object storage in general
(and swift specifically) provides is large scale, cheap, and durable
storage

<notmyname> technologov: object storage is all about relaxing some of
the constraints of a posix-style system. for example, if you don't
have to provide atomic operations (ie you can rely on eventual
consistency), you can much more easily scale a storage system and not
have a central point of failure

Also:
I have seen a video, that explains a bit about hashing searches, but
very incomplete.
Also what happens if new servers get added or removed ?
Such concepts need to be added into the docs.

Does Object Storage also stores files ? (seems yes)

How is SWIFT coherent ? Or it does not guarantee coherency ?

2. Nova-volume vs Nova-object vs Images (glance) vs. Object Storage (swift)
=============================================

Both (1) Nova-volume and (2) Nova-object and (3) glance and (4) swift seem capable of
storing VM hard disks.
What's the conceptual difference between the three ?

Possible Answer:
"<notmyname> technologov: nova-volume is for block storage attached to
a VM. glance is to manage the VM images in a nova cluster and provide
nice ways of storing them (a bridge to the storage, not the storage
itself). swift is an object storage system that can be used by glance
or on its own. swift isn't a filesystem, so it's not "mountable" like
the devices managed with nova-volume"

Arguments & Discussion:
<technologov> come on... "mountable" term is a joke... nowadays you
can mount GMail or Wikipedia... via FUSE
<technologov> w.p. is not a Filesystem either :)

<notmyname> ok, so you don't use swift like a traditional hard drive.
the only access to it is API-based (and the API is http)
<notmyname> that can be wrapped into a FUSE filesystem (but there are
big tradeoffs in doing so--advantages too, of course)

Once we can agree on the concepts, need to patch official docs.

=======================================================
Some users say this is like Amazon AWS or Amazon S3 or whatever...

the problem is: I have never used Amazon. I have used RHEV (Red Hat Enterprise Virtualization), which is based on local storage or NFS or iSCSI concepts... All the "object storage" concepts are 100% brand new to me.

We need to define the concepts, and make sure they are understandable for all users alike from different backgrounds.

-Technologov, 22.02.2012.