A profile in WebSphere to me, is akin to en entire new isntallation of the software. Basically, to do in earlier versions of WebSphere what we now do with a profile, we'd have to install WebSphere into a completely new and separate directory. It's like a brand new installation.
From there, the new installation in the past, or profile in present day, can exist on its own, representing prop, pre-prod and
testing environments, or, you can federate the profiles and do some WLM, although just clustering JVMs in a single profile makes more sense.
Happy WebSphere!
-Cameron McKenzie