What is the dataset's top layer called? Is it the file system?

Top Layer Terms

  • Dataset = Live filesystem
    • Every thing points to wards using the term Live filesystem because snapshots also refer to filesystems.
  • Zvols = Live volume
    • This follows the nomenclature as dataset

Both name tie in with the ZFS configuration options:

type=filesystem   (dataset)
type=volume       (zvol)

Common Top Layer Terms
The following are terms that can apply to both a dataset and zvol but are not as clear.

  • Current dataset state (Best generic description)
  • Live state
  • Current state

Some prior snapshot explanations from @winnielinnie