All the documents evolve according to a defined life cycle. The default life cycle is composed of the following states: Project, Approved, Obsolete and Deleted. There are different ways to make documents evolve through this life cycle. One of the ways is to use a workflow.
A workflow is a process in which a chain of users is defined to review, approve or reject the document. Workflows are traditionally used to validate documents (make them go to "Approved" state), but they can also be used to have the document reviewed, without life cycle state change.
The default serial workflow, called "Serial document review", is an ordered workflow. This means that participants can review the document only when the previous participant in the list has approved the document. It can be used either to approve the document or simply to review it.
The default parallel workflow, called "Parallel document review", is an unordered workflow that enables to change the document's state after a consultation step. This means that participants can give their opinion on the document without having to wait for a previous participant to approve it.
Users who are involved in workflows are alerted by email and can have a synthetic view of all the tasks they have to do on documents in their dashboard. The documents they have to review are listed there.