deployment.yaml file name, purpose potentially confusing

Anecdotally, I was trying the wskdeploy tool in earnest for the first time a few days ago, and it took me a while to identify the purpose of the deployment.yaml file relative to the manifest.yaml file.

At first I was surprised that there were two different files necessary, as I had expected only one.

Then I thought perhaps only the deployment.yaml was necessary for deployment, per the 'deployment' name, but found that in fact it was the opposite, and that the manifest was the required for portion when attempting to deploy, whereas the deployment file was optional (at least, as far as my personal testing indicated).

Then I intuited that perhaps the deployment file was a sort of environment or data component that augmented the manifest file, whereas the manifest was a general-purpose file that would not vary between deployments. This is based on prior conversations we've had in our regular meeting, but I don't know how fast I would've arrived at this conclusion if I were approaching this as a new user. If this is the case, I would expect the deployment file to be something like environment.yaml or data.yaml. A similar file is in our current samples (which use bash scripts to deploy) is called "local.env" .