Workflows are WCM system objects that describe the "life cycle" of a content object in terms of state transitions. State transitions describe the conditions required for a content object to pass from one state to another within a workflow.
Once WCM users have completed their tasks in a workflow, they can advance the object to the next workflow state. For example, once an editor has completely created an article, he/she would advance it from "Draft" to "Submitted" status, after which a managing editor would read and approve the article.
The default WCM workflow states for content objects are Draft, Submitted, Approved, Published, Archived. However, if you have customized workflows, other states and state transitions could be used.