When a workflow is applied to a page or blog post, the Content Byline Item will be added to the page/blog heading:
The name of the current state of the page is shown next to a colored status indicator circle. In the example, this is
You can click the state link to open the workflow popup:
Any user with Edit permission can approve or reject the content. If you assign a specific user using +Add Reviewer, only this user will be able to approve or reject the content.
If the circle on the content byline is filled, it means you are assigned to a content review.