By using the skipifalreadyinstalled option with the deploy command, you can prevent the reinstallation of an artifact that is already present in the target organization.
The --baselineorg parameter allows you to specify the alias or username of an org against which to check whether the incoming package versions have already been installed and form a deployment plan.This overrides the default behaviour which is to compare against the deployment target org. This is an optional feature which allows to ensure each org's are updated with the same installation across every org's in the path to production.