Content review
In Sitecore Content Hub, content moves through an approved workflow from the point of creation until the content is archived at the end of the content life cycle. A content item begins in the Ideation flow (as shown on the first tab) or in the CMP flow (as shown on the second tab). In the Ideation flow, there is a review in the Pending approval state. In the CMP flow, the Review state occurs, by default, in the middle of the flow and, when you click Send for review, the state of the content item changes to In Review.
In Review
By default, a content item moves to the In Review state from the In progress state when you click Send for review. At this stage, the editors verify the content and approve or reject it.

Once approved, the content is ready to publish.