| Only one per document |
As many as required |
| Tightly bound to the document |
Attached to a document or fragment, or can be general, but they are movable |
| Status reflects document lifecycle |
Status reflects an action to be undertaken |
| Only assignee is notified by default |
All authors and assignees notified by default |
| Incrementally updated by a stage |
Has the flexibility of comments – to edit, archive, move |
| Location is fixed |
Can be moved to a different document |
| Use workflow labels |
Use comment labels |