i wonder if these words are synonymous with eachother?
Yes, they are equivalent terms for most uses.
When you're getting "changeset" 5100 or "revision" 5100, you're discussing the same thing. A changeset is technically the changes contained there-in (same with most source control systems) and revision is technically the version after the changeset is applied, but most of the time, you're talking about the same thing.
Each committed changeset is marked with a revision number that uniquely identifies that particular changeset. Strictly speaking, you could say the changeset refers to the changes to the files themselves, and the revision number is what identifies it, but I would guess that most people casually use the two interchangeability.
Not really. A changeset is (as the name implies) a set of changes, whereas a revision is the state of the code base at a particular juncture.
A changeset is applied to one revision in order to produce a new revision.
A revision can thus be thought of as the cumulative effect of a sequence of changesets.
Having said all that, the term revision is often used as a synonym for changeset, ("Did you see my revision? It adds some new files."), but I find that usage ambiguous and confusing.
at least for SVN those words are synonymous. Changeset = a set of changes = revision.
Basically a changeset is everything related to a single check in operation, in SVN that's a revision.